Financial Ratios and Metrics Guide

BusinessMath Quarterly Series

14 min read

Part 7 of 12-Week BusinessMath Series

What You’ll Learn

How to calculate and interpret profitability ratios (ROA, ROE, ROIC)
Using efficiency ratios to measure asset utilization
Assessing liquidity and solvency for financial health
Applying DuPont analysis to decompose ROE
Using credit metrics like Altman Z-Score and Piotroski F-Score

The Problem

Analyzing financial statements requires calculating dozens of ratios across five categories: profitability, efficiency, liquidity, solvency, and valuation. Each ratio has a specific formula, interpretation guidelines, and industry benchmarks.

Doing this manually is tedious and error-prone. Spreadsheets help, but lack type safety and composability. You need to:

Calculate ratios consistently across periods
Track trends over time
Compare companies on equal footing
Assess financial health with composite scores

BusinessMath offers a systematic way to compute, track, and interpret financial metrics programmatically.

The Solution

BusinessMath provides comprehensive ratio analysis functions that work with IncomeStatement and BalanceSheet data structures, returning results as TimeSeries for trend analysis.

Setup: Creating Financial Statements

First, let’s create sample financial statements for a fictional SaaS company “TechCo”:

// Define company and periods
let entity = Entity(id: "TECH", primaryType: .ticker, name: "TechCo Inc.")
let periods = [
	Period.quarter(year: 2025, quarter: 1),
	Period.quarter(year: 2025, quarter: 2),
	Period.quarter(year: 2025, quarter: 3),
	Period.quarter(year: 2025, quarter: 4)
]

// Convenient period references
let q1 = periods[0]
let q2 = periods[1]
let q3 = periods[2]
let q4 = periods[3]

// Create Income Statement
// Revenue: $5M → $6M over the year (20% growth)
let revenueSeries = TimeSeries
            
              ( periods: periods, values: [5_000_000, 5_300_000, 5_600_000, 6_000_000] ) let revenueAccount = try Account( entity: entity, name: "Subscription Revenue", type: .revenue, timeSeries: revenueSeries ) // COGS: 30% of revenue var cogsMetadata = AccountMetadata() cogsMetadata.category = "COGS" let cogsSeries = TimeSeries
              
                ( periods: periods, values: [1_500_000, 1_590_000, 1_680_000, 1_800_000] ) let cogsAccount = try Account( entity: entity, name: "Cost of Goods Sold", type: .expense, timeSeries: cogsSeries, metadata: cogsMetadata ) // Operating Expenses: R&D + S&M + G&A var opexMetadata = AccountMetadata() opexMetadata.category = "Operating" let opexSeries = TimeSeries
                
                  ( periods: periods, values: [2_000_000, 2_100_000, 2_150_000, 2_200_000] ) let opexAccount = try Account( entity: entity, name: "Operating Expenses", type: .expense, timeSeries: opexSeries, metadata: opexMetadata ) // Interest expense let interestSeries = TimeSeries
                  
                    ( periods: periods, values: [100_000, 95_000, 90_000, 85_000] ) let interestAccount = try Account( entity: entity, name: "Interest Expense", type: .expense, timeSeries: interestSeries ) let incomeStatement = try IncomeStatement( entity: entity, periods: periods, revenueAccounts: [revenueAccount], expenseAccounts: [cogsAccount, opexAccount, interestAccount] ) // Create Balance Sheet // Current Assets var currentAssetMetadata = AccountMetadata() currentAssetMetadata.category = "Current" let cashSeries = TimeSeries
                    
                      ( periods: periods, values: [3_000_000, 3_500_000, 4_000_000, 4_500_000] ) let cashAccount = try Account( entity: entity, name: "Cash", type: .asset, timeSeries: cashSeries, metadata: currentAssetMetadata ) let receivablesSeries = TimeSeries
                      
                        ( periods: periods, values: [1_200_000, 1_300_000, 1_400_000, 1_500_000] ) let receivablesAccount = try Account( entity: entity, name: "Accounts Receivable", type: .asset, timeSeries: receivablesSeries, metadata: currentAssetMetadata ) // Fixed Assets var fixedAssetMetadata = AccountMetadata() fixedAssetMetadata.category = "Fixed" let ppeSeries = TimeSeries
                        
                          ( periods: periods, values: [2_000_000, 2_050_000, 2_100_000, 2_150_000] ) let ppeAccount = try Account( entity: entity, name: "Property & Equipment", type: .asset, timeSeries: ppeSeries, metadata: fixedAssetMetadata ) // Current Liabilities var currentLiabilityMetadata = AccountMetadata() currentLiabilityMetadata.category = "Current" let payablesSeries = TimeSeries
                          
                            ( periods: periods, values: [800_000, 850_000, 900_000, 950_000] ) let payablesAccount = try Account( entity: entity, name: "Accounts Payable", type: .liability, timeSeries: payablesSeries, metadata: currentLiabilityMetadata ) // Long-term Debt var longTermLiabilityMetadata = AccountMetadata() longTermLiabilityMetadata.category = "Long-term" let debtSeries = TimeSeries
                            
                              ( periods: periods, values: [2_000_000, 1_900_000, 1_800_000, 1_700_000] ) let debtAccount = try Account( entity: entity, name: "Long-term Debt", type: .liability, timeSeries: debtSeries, metadata: longTermLiabilityMetadata ) // Equity (balancing to Assets = Liabilities + Equity) let equitySeries = TimeSeries
                              
                                ( periods: periods, values: [3_400_000, 4_100_000, 4_800_000, 5_500_000] ) let equityAccount = try Account( entity: entity, name: "Shareholders Equity", type: .equity, timeSeries: equitySeries ) let balanceSheet = try BalanceSheet( entity: entity, periods: periods, assetAccounts: [cashAccount, receivablesAccount, ppeAccount], liabilityAccounts: [payablesAccount, debtAccount], equityAccounts: [equityAccount] ) // Market data for valuation metrics let marketPrice = 45.00 // $45 per share let sharesOutstanding = 200_000.0 // 200K shares outstanding // Cash flow statement (for Piotroski F-Score) let operatingCashFlowSeries = TimeSeries
                                
                                  ( periods: periods, values: [1_500_000, 1_600_000, 1_700_000, 1_900_000] ) let cashFlowAccount = try Account( entity: entity, name: "Operating Cash Flow", type: .operating, // Must use .operating for operating cash flow accounts timeSeries: operatingCashFlowSeries ) let cashFlowStatement = try CashFlowStatement( entity: entity, periods: periods, operatingAccounts: [cashFlowAccount], investingAccounts: [], financingAccounts: [] )

About TechCo’s Financials:

Revenue: Growing SaaS company, $5M → $6M quarterly (20% annual growth)
Gross Margin: 70% (typical for SaaS: low COGS, high operating leverage)
Balance Sheet: Healthy cash position ($3M → $4.5M), paying down debt ($2M → $1.7M)
Equity: Growing from retained earnings as company becomes profitable

The setup defines all variables used in examples below: incomeStatement, balanceSheet, cashFlowStatement, q1-q4, periods, marketPrice, and sharesOutstanding.

Profitability Ratios

How efficiently does the company generate profits?

import BusinessMath

// Get all profitability ratios at once
let profitability = profitabilityRatios(
	incomeStatement: incomeStatement,
	balanceSheet: balanceSheet
)

print("=== Profitability Analysis ===")
print("Gross Margin: \(profitability.grossMargin[q1]!.percent(1))")
print("Operating Margin: \(profitability.operatingMargin[q1]!.percent(1))")
print("Net Margin: \(profitability.netMargin[q1]!.percent(1))")
print("EBITDA Margin: \(profitability.ebitdaMargin[q1]!.percent(1))")
print("ROA: \(profitability.roa[q1]!.percent(1))")
print("ROE: \(profitability.roe[q1]!.percent(1))")
print("ROIC: \(profitability.roic[q1]!.percent(1))")

Interpretation:

Gross Margin > 40%: Strong pricing power
ROA > 5%: Good asset efficiency (varies by industry)
ROE > 15%: Strong returns for shareholders
ROIC > WACC: Company creates value

Efficiency Ratios

How effectively does the company use its assets?

let efficiency = efficiencyRatios(
    incomeStatement: incomeStatement,
    balanceSheet: balanceSheet
)

print("\n=== Efficiency Analysis ===")
print("Asset Turnover: \(efficiency.assetTurnover[q1]!.number(2))")
print("Inventory Turnover: \(efficiency.inventoryTurnover![q1]!.number(1))")
print("Receivables Turnover: \(efficiency.receivablesTurnover![q1]!.number(1))")
print("Days Sales Outstanding: \(efficiency.daysSalesOutstanding![q1]!.number(1)) days")
print("Days Inventory Outstanding: \(efficiency.daysInventoryOutstanding![q1]!.number(1)) days")
print("Days Payable Outstanding: \(efficiency.daysPayableOutstanding![q1]!.number(1)) days")

// Cash Conversion Cycle
let ccc = efficiency.cashConversionCycle![q1]!
print("Cash Conversion Cycle: \(ccc.number(1)) days")

Interpretation:

Higher turnover = more efficient use of assets
Lower DSO (Days Sales Outstanding) = faster cash collection
Shorter CCC (Cash Conversion Cycle) = less cash tied up in operations
Always compare to industry benchmarks

Liquidity Ratios

Can the company meet short-term obligations?

print("\n=== Liquidity Analysis ===")
print("Current Ratio: \(liquidity.currentRatio[q1]!)")
print("Quick Ratio: \(liquidity.quickRatio[q1]!)")
print("Cash Ratio: \(liquidity.cashRatio[q1]!)")
print("Working Capital: \(liquidity.workingCapital[q1]!.currency(0))")

// Assess liquidity health
let currentRatio = liquidity.currentRatio[q1]!
if currentRatio < 1.0 {
	print("⚠️  Warning: Current ratio < 1.0 indicates potential liquidity issues")
} else if currentRatio > 3.0 {
	print("ℹ️  Note: High current ratio may indicate inefficient use of assets")
} else {
	print("✓ Current ratio in healthy range")
}

Interpretation:

Current Ratio > 1.5: Good short-term health
Quick Ratio > 1.0: Can pay bills without selling inventory
Cash Ratio > 0.5: Strong
Too high may indicate poor asset utilization

Solvency Ratios

Can the company meet long-term obligations?

let solvency = solvencyRatios(
    incomeStatement: incomeStatement,
    balanceSheet: balanceSheet
)

print("\n=== Solvency Analysis ===")
print("Debt-to-Equity: \(solvency.debtToEquity[q2]!.number(2))")
print("Debt-to-Assets: \(solvency.debtToAssets[q2]!.number(2))")
print("Equity Ratio: \(solvency.equityRatio[q2]!.number(2))")
print("Interest Coverage: \(solvency.interestCoverage![q2]!.number(1))x")
print("Debt Service Coverage: \(solvency.debtServiceCoverage![q2]!.number(1))x")

// Assess leverage
let debtToEquity = solvency.debtToEquity[q1]!
if debtToEquity > 2.0 {
    print("⚠️  High leverage - company relies heavily on debt")
} else if debtToEquity < 0.5 {
    print("ℹ️  Conservative capital structure - may be underlevered")
} else {
    print("✓ Balanced capital structure")
}

// Check interest coverage
let interestCoverage = solvency.interestCoverage[q1]!
if interestCoverage < 2.0 {
    print("⚠️  Low interest coverage - may struggle to pay interest")
} else if interestCoverage > 5.0 {
    print("✓ Strong interest coverage")
}

Interpretation:

Lower D/E: Less risky, but may miss growth opportunities
Higher D/E: More leverage, higher risk and return potential
Interest Coverage > 3x: Generally safe
Industry context matters (utilities vs tech)

DuPont Analysis

Decompose ROE to understand its drivers:

// 3-Way DuPont Analysis
let dupont = dupontAnalysis(
    incomeStatement: incomeStatement,
    balanceSheet: balanceSheet
)

print("\n=== 3-Way DuPont Analysis ===")
print("ROE = Net Margin × Asset Turnover × Equity Multiplier\n")
print("Net Margin: \(dupont.netMargin[q1]!.percent())")
print("Asset Turnover: \(dupont.assetTurnover[q1]!.number(1))x")
print("Equity Multiplier: \(dupont.equityMultiplier[q1]!.number(1))x")
print("ROE: \(dupont.roe[q1]!.percent(1))")

// Verify the formula
let calculated = dupont.netMargin[q1]! *
				 dupont.assetTurnover[q1]! *
				 dupont.equityMultiplier[q1]!
print("\nVerification: \(calculated.percent()) ≈ \(dupont.roe[q1]!.percent())")

ROE can be high due to:

High Net Margin: Pricing power (luxury goods)
High Asset Turnover: Efficient operations (retail)
High Equity Multiplier: Using leverage (banks)

DuPont analysis reveals which factor drives ROE, helping you understand the business model.

Credit Metrics

Assess bankruptcy risk and fundamental strength:

// Altman Z-Score (bankruptcy prediction)
let altmanZ = altmanZScore(
    incomeStatement: incomeStatement,
    balanceSheet: balanceSheet,
    marketPrice: marketPrice,
    sharesOutstanding: sharesOutstanding
)

print("\n=== Altman Z-Score ===")
print("Z-Score: \(altmanZ[q1]!)")

let zScore = altmanZ[q1]!
if zScore > 2.99 {
    print("✓ Safe zone - low bankruptcy risk")
} else if zScore > 1.81 {
    print("⚠️  Grey zone - moderate risk")
} else {
    print("⚠️  Distress zone - high bankruptcy risk")
}

// Piotroski F-Score (fundamental strength, 0-9)
let piotroski = piotroskiFScore(
    incomeStatement: incomeStatement,
    balanceSheet: balanceSheet,
    cashFlowStatement: cashFlowStatement
)

print("\n=== Piotroski F-Score ===")
print("F-Score: \(Int(piotroski.totalScore)) / 9")

let fScore = Int(piotroski.totalScore)
if fScore >= 7 {
    print("✓ Strong fundamentals")
} else if fScore >= 4 {
    print("ℹ️  Moderate fundamentals")
} else {
    print("⚠️  Weak fundamentals")
}

Interpretation:

Altman Z-Score:
- > 3.0: Financially sound
- 1.8-3.0: Watch zone
- < 1.8: High bankruptcy risk
Piotroski F-Score:
- 8-9: Very strong
- 5-7: Solid
- 0-4: Weak

How It Works

TimeSeries Return Values

All ratio functions return TimeSeries, allowing trend analysis:

// Analyze trends across quarters
print("\n=== Profitability Trends ===")
print("Period       ROE      ROA    Net Margin")
for period in periods {
    let roe = profitability.roe[period]!
    let roa = profitability.roa[period]!
    let margin = profitability.netMargin[period]!

	print("\(period.label.padding(toLength: 7, withPad: " ", startingAt: 0)) \(roe.percent(1).paddingLeft(toLength: 8)) \(roa.percent(1).paddingLeft(toLength: 8)) \(margin.percent(1).paddingLeft(toLength: 12))")
}

// Calculate quarter-over-quarter growth
let q1_roe = profitability.roe[q1]!
let q2_roe = profitability.roe[q2]!
let qoq_growth = ((q2_roe - q1_roe) / q1_roe)
print("\nQ2 ROE growth vs Q1: \(qoq_growth.percent())")

Industry Benchmarks

Typical ranges vary by industry:

Technology:

Gross Margin: 60-80%
ROE: 15-30%
D/E: 0.1-0.5 (low leverage)
Asset Turnover: 0.5-1.0

Retail:

Gross Margin: 25-40%
ROE: 15-25%
D/E: 0.5-1.5
Asset Turnover: 2.0-4.0 (high)

Financial Services:

Net Margin: 15-25%
ROE: 10-15%
D/E: 5.0-10.0 (high leverage)
Equity Multiplier: 10-20x

Try It Yourself

Click to expand full playground code

import BusinessMath

// Define company and periods
let entity = Entity(id: "TECH", primaryType: .ticker, name: "TechCo Inc.")
let periods = [
	Period.quarter(year: 2025, quarter: 1),
	Period.quarter(year: 2025, quarter: 2),
	Period.quarter(year: 2025, quarter: 3),
	Period.quarter(year: 2025, quarter: 4)
]

// Convenient period references
let q1 = periods[0]
let q2 = periods[1]
let q3 = periods[2]
let q4 = periods[3]

// Create Income Statement
// Revenue: $5M → $6M over the year (20% growth)
let revenueSeries = TimeSeries
              
                ( periods: periods, values: [5_000_000, 5_300_000, 5_600_000, 6_000_000] ) let revenueAccount = try Account( entity: entity, name: "Subscription Revenue", incomeStatementRole: .serviceRevenue, timeSeries: revenueSeries ) // COGS: 30% of revenue let cogsSeries = TimeSeries
                
                  ( periods: periods, values: [1_500_000, 1_590_000, 1_680_000, 1_800_000] ) let cogsAccount = try Account( entity: entity, name: "Cost of Goods Sold", incomeStatementRole: .costOfGoodsSold, timeSeries: cogsSeries ) // Operating Expenses: R&D + S&M + G&A let opexSeries = TimeSeries
                  
                    ( periods: periods, values: [2_000_000, 2_100_000, 2_150_000, 2_200_000] ) let opexAccount = try Account( entity: entity, name: "Operating Expenses", incomeStatementRole: .operatingExpenseOther, timeSeries: opexSeries ) // Interest expense let interestSeries = TimeSeries
                    
                      ( periods: periods, values: [100_000, 95_000, 90_000, 85_000] ) let interestAccount = try Account( entity: entity, name: "Interest Expense", incomeStatementRole: .interestExpense, timeSeries: interestSeries ) let incomeStatement = try IncomeStatement( entity: entity, periods: periods, accounts: [revenueAccount, cogsAccount, opexAccount, interestAccount] ) // Create Balance Sheet // Current Assets let cashSeries = TimeSeries
                      
                        ( periods: periods, values: [3_000_000, 3_500_000, 4_000_000, 4_500_000] ) let cashAccount = try Account( entity: entity, name: "Cash", balanceSheetRole: .cashAndEquivalents, timeSeries: cashSeries ) let receivablesSeries = TimeSeries
                        
                          ( periods: periods, values: [1_200_000, 1_300_000, 1_400_000, 1_500_000] ) let receivablesAccount = try Account( entity: entity, name: "Accounts Receivable", balanceSheetRole: .accountsReceivable, // Required for receivables turnover timeSeries: receivablesSeries ) // Inventory (needed for inventory turnover) let inventorySeries = TimeSeries
                          
                            ( periods: periods, values: [500_000, 520_000, 540_000, 560_000] ) let inventoryAccount = try Account( entity: entity, name: "Inventory", balanceSheetRole: .inventory, // Required for inventory turnover timeSeries: inventorySeries ) // Fixed Assets let ppeSeries = TimeSeries
                            
                              ( periods: periods, values: [2_000_000, 2_050_000, 2_100_000, 2_150_000] ) let ppeAccount = try Account( entity: entity, name: "Property & Equipment", balanceSheetRole: .propertyPlantEquipment, timeSeries: ppeSeries ) // Current Liabilities let payablesSeries = TimeSeries
                              
                                ( periods: periods, values: [800_000, 850_000, 900_000, 950_000] ) let payablesAccount = try Account( entity: entity, name: "Accounts Payable", balanceSheetRole: .accountsPayable, // Required for days payable outstanding timeSeries: payablesSeries ) // Long-term Debt let debtSeries = TimeSeries
                                
                                  ( periods: periods, values: [2_000_000, 1_900_000, 1_800_000, 1_700_000] ) let debtAccount = try Account( entity: entity, name: "Long-term Debt", balanceSheetRole: .longTermDebt, timeSeries: debtSeries ) // Equity (balancing to Assets = Liabilities + Equity) // Adjusted for inventory: Assets now include $500K+ inventory each quarter let equitySeries = TimeSeries
                                  
                                    ( periods: periods, values: [3_900_000, 4_620_000, 5_340_000, 6_060_000] ) let equityAccount = try Account( entity: entity, name: "Shareholders Equity", balanceSheetRole: .commonStock, timeSeries: equitySeries ) let balanceSheet = try BalanceSheet( entity: entity, periods: periods, accounts: [cashAccount, receivablesAccount, inventoryAccount, ppeAccount, payablesAccount, debtAccount, equityAccount] ) // Market data for valuation metrics let marketPrice = 45.00 // $45 per share let sharesOutstanding = 200_000.0 // 200K shares outstanding // Cash flow statement (for Piotroski F-Score) let operatingCashFlowSeries = TimeSeries
                                    
                                      ( periods: periods, values: [1_500_000, 1_600_000, 1_700_000, 1_900_000] ) let cashFlowAccount = try Account( entity: entity, name: "Operating Cash Flow", cashFlowRole: .otherOperatingActivities, // Use cashFlowRole for cash flow accounts timeSeries: operatingCashFlowSeries ) let cashFlowStatement = try CashFlowStatement( entity: entity, periods: periods, accounts: [cashFlowAccount] ) // Get all profitability ratios at once let profitability = profitabilityRatios( incomeStatement: incomeStatement, balanceSheet: balanceSheet ) print("=== Profitability Analysis ===") print("Gross Margin: \(profitability.grossMargin[q2]!.percent(1))") print("Operating Margin: \(profitability.operatingMargin[q2]!.percent(1))") print("Net Margin: \(profitability.netMargin[q2]!.percent(1))") print("EBITDA Margin: \(profitability.ebitdaMargin[q2]!.percent(1))") print("ROA: \(profitability.roa[q2]!.percent(1))") print("ROE: \(profitability.roe[q2]!.percent(1))") print("ROIC: \(profitability.roic[q2]!.percent(1))") let efficiency = efficiencyRatios( incomeStatement: incomeStatement, balanceSheet: balanceSheet ) print("\n=== Efficiency Analysis ===") print("Asset Turnover: \(efficiency.assetTurnover[q2]!.number(2))") print("Inventory Turnover: \(efficiency.inventoryTurnover![q2]!.number(1))") print("Receivables Turnover: \(efficiency.receivablesTurnover![q2]!.number(1))") print("Days Sales Outstanding: \(efficiency.daysSalesOutstanding![q2]!.number(1)) days") print("Days Inventory Outstanding: \(efficiency.daysInventoryOutstanding![q2]!.number(1)) days") print("Days Payable Outstanding: \(efficiency.daysPayableOutstanding![q2]!.number(1)) days") // Cash Conversion Cycle let ccc = efficiency.cashConversionCycle![q2]! print("Cash Conversion Cycle: \(ccc.number(1)) days") let liquidity = liquidityRatios(balanceSheet: balanceSheet) print("\n=== Liquidity Analysis ===") print("Current Ratio: \(liquidity.currentRatio[q2]!.number(1))") print("Quick Ratio: \(liquidity.quickRatio[q2]!.number(1))") print("Cash Ratio: \(liquidity.cashRatio[q2]!.number(1))") print("Working Capital: \(liquidity.workingCapital[q2]!.currency(0))") // Assess liquidity health let currentRatio = liquidity.currentRatio[q2]! if currentRatio < 1.0 { print("⚠️ Warning: Current ratio < 1.0 indicates potential liquidity issues") } else if currentRatio > 3.0 { print("ℹ️ Note: High current ratio may indicate inefficient use of assets") } else { print("✓ Current ratio in healthy range") } // Calculate solvency ratios using the convenience API // Principal payments are automatically derived from period-over-period debt reduction let solvency = solvencyRatios( incomeStatement: incomeStatement, balanceSheet: balanceSheet, debtAccount: debtAccount, // Automatically calculates principal payments interestAccount: interestAccount // from balance sheet changes ) print("\n=== Solvency Analysis ===") print("Debt-to-Equity: \(solvency.debtToEquity[q2]!.number(2))") print("Debt-to-Assets: \(solvency.debtToAssets[q2]!.number(2))") print("Equity Ratio: \(solvency.equityRatio[q2]!.number(2))") print("Interest Coverage: \(solvency.interestCoverage![q2]!.number(1))x") print("Debt Service Coverage: \(solvency.debtServiceCoverage![q2]!.number(1))x") // 3-Way DuPont Analysis let dupont = dupontAnalysis( incomeStatement: incomeStatement, balanceSheet: balanceSheet ) print("\n=== 3-Way DuPont Analysis ===") print("ROE = Net Margin × Asset Turnover × Equity Multiplier\n") print("Net Margin: \(dupont.netMargin[q1]!.percent())") print("Asset Turnover: \(dupont.assetTurnover[q1]!.number(1))x") print("Equity Multiplier: \(dupont.equityMultiplier[q1]!.number(1))x") print("ROE: \(dupont.roe[q1]!.percent(1))") // Verify the formula let calculated = dupont.netMargin[q1]! * dupont.assetTurnover[q1]! * dupont.equityMultiplier[q1]! print("\nVerification: \(calculated.percent()) ≈ \(dupont.roe[q1]!.percent())") // Assess leverage let debtToEquity = solvency.debtToEquity[q2]! if debtToEquity > 2.0 { print("⚠️ High leverage - company relies heavily on debt") } else if debtToEquity < 0.5 { print("ℹ️ Conservative capital structure - may be underlevered") } else { print("✓ Balanced capital structure") } // Check interest coverage let interestCoverage = solvency.interestCoverage?[q2]! ?? 0.0 if interestCoverage < 2.0 { print("⚠️ Low interest coverage - may struggle to pay interest") } else if interestCoverage > 5.0 { print("✓ Strong interest coverage") } // Analyze trends across quarters print("\n=== Profitability Trends ===") print("Period ROE ROA Net Margin") for period in periods { let roe = profitability.roe[period]! let roa = profitability.roa[period]! let margin = profitability.netMargin[period]! print("\(period.label.padding(toLength: 7, withPad: " ", startingAt: 0)) \(roe.percent(1).paddingLeft(toLength: 8)) \(roa.percent(1).paddingLeft(toLength: 8)) \(margin.percent(1).paddingLeft(toLength: 12))") } // Calculate quarter-over-quarter growth let q1_roe = profitability.roe[q1]! let q2_roe = profitability.roe[q2]! let qoq_growth = ((q2_roe - q1_roe) / q1_roe) print("\nQ2 ROE growth vs Q1: \(qoq_growth.percent())")

→ Full API Reference: BusinessMath Docs – 2.2 Financial Ratios

Modifications to try:

Compare profitability ratios for two companies
Track liquidity trends over multiple quarters
Perform DuPont analysis to identify ROE drivers

Real-World Application

Investment analysts use financial ratios for every stock evaluation:

Profitability screening: ROE > 15%, ROIC > WACC
Safety checks: Current Ratio > 1.5, Z-Score > 2.99
Efficiency comparisons: Compare DSO across industry peers
Valuation: Low P/E + high Piotroski F-Score = potential value

BusinessMath makes these calculations systematic, repeatable, and type-safe.

📝 Development Note

During development, we debated whether to return individual ratios (separate functions for each) or composite structs (one function returning all profitability ratios).

The composite approach won because real-world analysis requires calculating many related ratios simultaneously. Calling 7 separate functions for profitability analysis was tedious and led to code duplication.

But we kept individual functions available too:

// Composite (most common)
let all = profitabilityRatios(incomeStatement: is, balanceSheet: bs)

// Individual (when you only need one)
let roe = returnOnEquity(incomeStatement: is, balanceSheet: bs)

The lesson: Provide both convenience (composite) and precision (individual). Let users choose based on their needs.

Related Methodology: The Master Plan (Week 3) - Managing API surface area

Next Steps

Coming up next: Risk Analytics (Friday) - VaR, stress testing, and comprehensive risk metrics.

Case Study: Week 3 Friday will combine depreciation + TVM + financial ratios for capital equipment decisions.

Series Progress:

Week: 2/12
Posts Published: 7/~48
Topics Covered: Foundation + Analysis Tools (in progress)
Playgrounds: 6 available

Tagged with: financial-analysis