The learning library

Calculator explanations and mathematical principles

Explore detailed explanations for every Toolify calculator: input definitions, calculation methods, mathematical concepts, numerical examples and model limitations.

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Mortgage & home buying

Mortgage extra payment calculatorFormula · Example · Mathematical principles Bi-weekly mortgage calculatorFormula · Example · Mathematical principles Mortgage calculator with PMI & taxesFormula · Example · Mathematical principles FHA mortgage payment calculatorFormula · Example · Mathematical principles VA home loan payment calculatorFormula · Example · Mathematical principles Mortgage refinance break-even calculatorFormula · Example · Mathematical principles Mortgage escrow payment calculatorFormula · Example · Mathematical principles Mortgage amortization schedule calculatorFormula · Example · Mathematical principles Home purchase closing cost calculatorFormula · Example · Mathematical principles Mortgage points break-even calculatorFormula · Example · Mathematical principles Home affordability calculatorFormula · Example · Mathematical principles Rent vs buy calculatorFormula · Example · Mathematical principles

Debt & interest

Credit card payoff calculatorFormula · Example · Mathematical principles Debt snowball & avalanche calculatorFormula · Example · Mathematical principles Student loan refinance calculatorFormula · Example · Mathematical principles HELOC payoff calculatorFormula · Example · Mathematical principles Simple interest calculatorFormula · Example · Mathematical principles

Income & pay

Hourly wage to annual salary calculatorFormula · Example · Mathematical principles Overtime pay calculatorFormula · Example · Mathematical principles Net income take-home calculatorFormula · Example · Mathematical principles Small business startup cost calculatorFormula · Example · Mathematical principles

Investing & retirement

Compound interest calculatorFormula · Example · Mathematical principles Investment compound return calculatorFormula · Example · Mathematical principles Investment return calculatorFormula · Example · Mathematical principles Net worth calculator for millennialsFormula · Example · Mathematical principles 401k contribution calculatorFormula · Example · Mathematical principles 401(k) vs Roth IRA calculatorFormula · Example · Mathematical principles Retirement savings calculatorFormula · Example · Mathematical principles Inflation adjusted calculatorFormula · Example · Mathematical principles

Property investing

Rental property ROI calculatorFormula · Example · Mathematical principles Rental property cash flow calculatorFormula · Example · Mathematical principles Rental property cap rate calculatorFormula · Example · Mathematical principles Rental property vacancy rate calculatorFormula · Example · Mathematical principles Short-term rental income calculatorFormula · Example · Mathematical principles Short-term rental profit margin calculatorFormula · Example · Mathematical principles Buy-and-hold real estate ROI calculatorFormula · Example · Mathematical principles Multifamily rental cash flow calculatorFormula · Example · Mathematical principles House flipping profit calculatorFormula · Example · Mathematical principles House flipping rehab budget calculatorFormula · Example · Mathematical principles Rental property tax deduction calculatorFormula · Example · Mathematical principles

Self-employed taxes

Self-employed tax estimatorFormula · Example · Mathematical principles Freelancer quarterly tax calculatorFormula · Example · Mathematical principles 1099 tax calculatorFormula · Example · Mathematical principles LLC tax calculatorFormula · Example · Mathematical principles Self-employment tax deduction calculatorFormula · Example · Mathematical principles Gig economy tax calculatorFormula · Example · Mathematical principles Safe harbor tax calculatorFormula · Example · Mathematical principles Freelance tax set-aside calculatorFormula · Example · Mathematical principles Business expense deduction calculatorFormula · Example · Mathematical principles

Small-business financing

Small business loan calculatorFormula · Example · Mathematical principles SBA loan calculatorFormula · Example · Mathematical principles Equipment financing calculatorFormula · Example · Mathematical principles Business line of credit calculatorFormula · Example · Mathematical principles

Business planning & pricing

Business startup break-even calculatorFormula · Example · Mathematical principles Small business profit margin calculatorFormula · Example · Mathematical principles Markup and margin calculatorFormula · Example · Mathematical principles Startup capital calculatorFormula · Example · Mathematical principles

Debt consolidation & borrowing readiness

Debt consolidation calculatorFormula · Example · Mathematical principles Debt-to-income ratio calculatorFormula · Example · Mathematical principles

Pregnancy health

Pregnancy BMI calculatorFormula · Example · Mathematical principles Pregnancy weight gain calculatorFormula · Example · Mathematical principles

Body weight & composition

Ideal weight calculator for menFormula · Example · Mathematical principles Ideal weight calculator for womenFormula · Example · Mathematical principles Body fat percentage calculatorFormula · Example · Mathematical principles Weight loss goal calculatorFormula · Example · Mathematical principles

Calories & nutrition

Basal metabolic rate BMR calculatorFormula · Example · Mathematical principles TDEE calculator for athletesFormula · Example · Mathematical principles Calorie deficit calculatorFormula · Example · Mathematical principles Muscle gain calorie calculatorFormula · Example · Mathematical principles Macros calculator for keto dietFormula · Example · Mathematical principles

Daily wellness

Water intake calculatorFormula · Example · Mathematical principles Resting heart rate calculatorFormula · Example · Mathematical principles Sleep debt calculatorFormula · Example · Mathematical principles

Painting projects

Paint calculatorFormula · Example · Mathematical principles Exterior paint calculatorFormula · Example · Mathematical principles

Floors & surfaces

Tile calculatorFormula · Example · Mathematical principles Flooring calculatorFormula · Example · Mathematical principles

Construction materials

Concrete calculatorFormula · Example · Mathematical principles Gravel calculatorFormula · Example · Mathematical principles Drywall calculatorFormula · Example · Mathematical principles Roof shingles calculatorFormula · Example · Mathematical principles

Yard & landscape

Mulch calculatorFormula · Example · Mathematical principles Sod calculatorFormula · Example · Mathematical principles