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.
Most-used calculators
View all 89 →- Mortgage Payment CalculatorEnter your home price, down payment, interest rate, and loan term to see your monthly payment and full interest cost.
- Auto Loan CalculatorFind your monthly car payment and total loan cost instantly — enter the vehicle price, down payment, trade-in, interest rate, and term.
- Personal Loan CalculatorEnter your loan amount, rate, and term to see the monthly payment, total interest, and a month-by-month payoff schedule.
- Pay Stub Calculator — Net Pay After TaxesCalculate your net take-home pay per paycheck after all taxes and deductions.
- 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.
- 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.
Browse by category
- Debt & Credit11
Payoff timelines, refinance savings, and debt-reduction strategy allocators.
- Everyday Math4
Tip splitting, percentages, age, and other quick calculations for daily decisions.
- Health & Fitness2
BMI, calorie needs, and other body-metric calculators grounded in standard clinical formulas.
- Insurance & Planning11
Coverage needs, emergency funds, education savings, and lifetime earnings tools.
- Investing14
Compounding, fee drag, and portfolio comparison calculators.
- Mortgage & Home14
Refinance break-even, amortization, and affordability tools for homeowners and buyers weighing a specific decision.
- Retirement11
Contribution, drawdown, and projection tools for long-horizon planning.
- Tax17
Estimators for equity compensation, self-employment, and withholding, with every statutory figure sourced and dated.
- Unit Converters5
Convert between metric and imperial units for weight, length, temperature, and clothing sizes.
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.
- How to Pay Off Student Loans FasterSix strategies to cut years off your student loan payoff — from extra payments and refinancing to income-driven plans and PSLF. With the math behind each.
- How Much House Can I Afford?The 28/36 rule, DTI limits, and how lenders actually calculate your maximum mortgage. Includes the number most buyers forget to include.
- Roth vs. Traditional IRA: Which Is Actually Better?The answer depends on one variable most people get wrong. Here is the math, the exceptions, and the case for splitting contributions.
- How to Read Your Pay StubEvery line on a pay stub explained: gross pay, federal and state withholding, FICA, pre-tax deductions, and why your net pay is lower than you expected.
- How Compound Interest Works (And Why It Changes Everything)Compound interest explained with real numbers: how the frequency of compounding affects returns, why starting early beats earning more, and the Rule of 72.
- When to Claim Social SecurityClaiming Social Security at 62 vs 67 vs 70: the break-even math, survivor benefit implications, and why the right age depends on more than just longevity.
- How to Pay Off Credit Card Debt FastThe avalanche and snowball methods compared, when balance transfers actually save money, and the math behind minimum-payment traps.
- How to Build an Emergency FundHow much to save, where to keep it, and how to build it without derailing your other financial goals. With the math behind the 3–6 month rule.
IRS & SSA-sourced figures
Tax brackets, contribution limits, and wage bases come from primary sources — IRS, SSA, Tax Foundation — with the tax year and source URL on every number.
Assumptions stated, not hidden
Each calculator lists exactly what it models and what it omits. You always know when a result is an estimate and when to consult a professional.
No account, no tracking
Nothing is stored server-side. Calculations run entirely in your browser. Close the tab and nothing persists.