Financial reference tools
Calculators that show their work.
Every calculator states its assumptions, cites the statutory source behind each figure, and records the date it was last reviewed. No sign-up, no stored data, no guesswork.
Popular calculators
View all 60 →- Mortgage Payment CalculatorEnter your home price, down payment, interest rate, and loan term to see your monthly payment and full interest cost.
- Home Affordability CalculatorDetermine your maximum affordable home price using front-end (28%) and back-end (43%) debt-to-income limits.
- Compound Growth CalculatorEnter your initial investment, annual contributions, return rate, and time horizon to see how compound growth builds wealth over time.
- Roth vs. Traditional IRA ComparisonDetermine whether a Roth or Traditional IRA leaves you with more after-tax money at retirement, given your current and expected future tax rates.
- Financial Independence Number CalculatorDetermine the portfolio size needed to retire based on your annual expenses and chosen withdrawal rate.
- W-4 Withholding EstimatorEstimate your total annual federal tax liability and required withholding per paycheck.
- Credit Card Payoff Timeline CalculatorSee your payoff date, total interest cost, and how much you save vs making only minimum payments.
- Budget 50/30/20 Rule CalculatorCheck if your actual spending aligns with the 50/30/20 budgeting framework.
- Emergency Fund CalculatorGet a personalized emergency fund target tailored to your income stability, household structure, and current savings.
Browse by category
- Debt & Credit7
Payoff timelines, refinance savings, and debt-reduction strategy allocators.
- Insurance & Planning9
Coverage needs, emergency funds, education savings, and lifetime earnings tools.
- Investing14
Compounding, fee drag, and portfolio comparison calculators.
- Mortgage & Home11
Refinance break-even, amortization, and affordability tools for homeowners and buyers weighing a specific decision.
- Retirement9
Contribution, drawdown, and projection tools for long-horizon planning.
- Tax10
Estimators for equity compensation, self-employment, and withholding, with every statutory figure sourced and dated.
Guides
- When Refinancing Actually Pays OffHow to read a refinance break-even month, which closing costs belong in the numerator, and the three cases where a lower rate still loses money.
- Why RSU Withholding Leaves You With a Tax BillSupplemental wage withholding on RSUs is a flat statutory rate, not your marginal rate. Here is where the gap comes from and how to close it.
Sourced constants
Tax brackets, contribution limits, and wage bases live in versioned modules with a source URL and tax year attached to every number.
Stated assumptions
Each tool lists exactly what it does and does not model, so you know when the answer needs a professional.
Fast by design
Server-rendered HTML, no client-side data fetching, and calculations that run instantly in your browser.