Free Online Calculators
11 free calculators covering age, BMI, loans, mortgage, tax, GPA, ROI and more. Every page includes a comparison table, use cases, and an editorial verdict.
Amortization Calculator
Generate a full loan amortization schedule showing principal, interest, and remaining balance for every payment. Visualize how each payment splits between interest and principal over the life of the loan.
CalculatorAuto Loan Calculator
Calculate monthly car payments with price, down payment, trade-in, sales tax, and APR. Compare new vs. used, 36 vs. 72 month terms, and dealer financing vs. credit union loans.
CalculatorBitcoin DCA Calculator
Project bitcoin accumulation through dollar-cost averaging. Model recurring buys, price scenarios, and total cost basis. See how much BTC you would have at any future price.
CalculatorBitcoin Mining Calculator
Estimate bitcoin mining profitability with current difficulty, network hashrate, hardware specs, and electricity costs. Calculate break-even, daily/monthly/annual earnings, and ROI.
CalculatorBTC to USD Calculator
Convert bitcoin to US dollars and USD to bitcoin at any price. Includes satoshi conversions, fee modeling, and historical price references.
CalculatorBudget Calculator
Build a monthly budget using the 50/30/20 rule or a custom breakdown. See exactly how much goes to needs, wants, savings, and debt payoff — and where to cut.
CalculatorCompound Interest Calculator
See how your investments grow over time with daily, monthly, or annual compounding. Model contributions, inflation, taxes, and time horizons from 1 to 50 years.
CalculatorCompound Interest Calculator for Small Business
Project business savings growth, equipment reserve accumulation, or reinvestment compounding. Models irregular contributions, tax treatment (SEP/SIMPLE/Solo 401k), and business-specific scenarios.
CalculatorCredit Card Payoff Calculator
Calculate how long it takes to pay off credit card debt and how much interest you will pay. Compare minimum payment vs. fixed payment strategies, and see the impact of the snowball or avalanche method.
CalculatorCrypto Profit Calculator
Calculate profit or loss on any cryptocurrency transaction — bitcoin, ethereum, altcoins. Supports multiple cost basis methods (FIFO, LIFO, average cost) and shows after-tax proceeds.
CalculatorCrypto Tax Calculator
Estimate federal and state income tax on cryptocurrency gains and income. Models short-term vs. long-term capital gains, staking rewards, mining income, and airdrops.
CalculatorDiscount Calculator
Calculate sale prices, stacked discounts, and savings on any purchase. Supports sequential markdowns, BOGO deals, fixed-dollar-off coupons, and percentage-off comparisons.
CalculatorEmergency Fund Calculator
Figure out how much cash to keep on hand for unexpected expenses. Calculate your target emergency fund based on monthly expenses, job stability, and dependents — then see how long it takes to build.
CalculatorFHA Loan Calculator (Texas 2026)
Calculate your FHA loan payment with Texas-specific conforming limits, MIP rates, and 2026 changes. Compare FHA vs. conventional financing for first-time buyers in Texas.
CalculatorFHA Loan Calculator for Self-Employed (Texas 2026)
Calculate FHA loan payments when qualifying with bank statements or P&L instead of tax returns. Covers self-employed documentation, Texas 2026 limits, and FHA loan qualification.
CalculatorInflation Calculator
Convert historical dollars to today's purchasing power and project future purchasing power. Uses official CPI data from 1913 to present plus forward projections.
CalculatorLoan Calculator
Calculate monthly payments, total interest, and full amortization schedule for any fixed-rate loan — auto, personal, student, or business. Compare terms side by side.
CalculatorMortgage Calculator
Calculate your monthly mortgage payment including principal, interest, property taxes, insurance, and PMI. Compare 15-year vs 30-year loans, see total interest paid, and plan your home purchase.
CalculatorNet Worth Calculator
Calculate your total net worth by adding all assets (cash, investments, real estate) and subtracting all liabilities (mortgage, loans, credit cards). Track changes over time with monthly snapshots.
CalculatorPaycheck Calculator
Calculate your take-home pay from gross salary. See federal tax, FICA, state tax (for major states), pre-tax deductions, and net pay per pay period — for W-2 employees.
CalculatorPercentage Calculator
Calculate percentages, percentage change, increases, decreases, and discounts. Solve for any unknown in a percentage problem — X is what percent of Y, what is X% of Y, and X is Y% of what.
CalculatorRetirement Calculator
Calculate how much you need to retire, how much you should save monthly, and whether you are on track. Includes 401(k) match modeling, Social Security estimation, and withdrawal sustainability.
CalculatorROI Calculator
Calculate return on investment for stocks, real estate, business projects, and marketing campaigns. Includes annualized ROI, CAGR, and comparison between multiple investments.
CalculatorSalary Calculator
Convert between hourly, weekly, biweekly, monthly, and annual salary. Calculate take-home pay after federal tax, FICA, and state taxes. Compare job offers on equal footing.
CalculatorStudent Loan Calculator
Calculate monthly payments and total interest for federal or private student loans. Compare refinancing options, income-driven repayment plans, and standard vs. graduated repayment.
CalculatorTax Calculator
Estimate federal income tax, FICA, and take-home pay for the 2026 tax year. Calculate marginal and effective rates, standard vs. itemized deductions, and quarterly estimated taxes.
CalculatorTip Calculator
Calculate restaurant tips and split bills instantly. Standard 15-25%, custom percentages, sales tax handling, and per-person split — for any number of diners.
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Pick a thread. Each topic links to the tools people actually pair together.
Which calculator should you use?
All 11 calculators on this site follow the same editorial standard: verified formula, worked examples, side-by-side comparison, and a verdict at the bottom of every page. No filler. No auto-generated fluff. Pick your category, pick your tool, get the number.
Standard reference formulas only
Every calculator uses the standard reference implementation of its formula. Edge cases return defined values or explicit warnings, not silent errors.
11 calculators across 4 domains
Math, health, finance, and time — the four domains where people most often need quick, reliable calculations.
Nothing leaves your browser
All calculations run client-side. No inputs are ever transmitted to any server.
Results update as you type
No submit button. No server round-trip. The result updates in real time as you change any input.