Finance Calculators
Mortgages, loans, interest, ROI, discount, tax — big-decision math without ads or lead-capture forms.
9 tools · all run in your browser
The finance calculators people actually need — with the answer front and center, not gated behind an email signup. Mortgage with a real year-by-year amortization schedule; loan calculator that shows what an extra $100/month saves; compound-interest projection for retirement planning; ROI + CAGR for investments; sales tax and discount calculators for shopping and shop math; APR ↔ APY converter for comparing credit-card and savings-account rates honestly.
None of this is financial advice. Every tool is a starting point: mortgages usually add taxes, insurance, and PMI (typically 15-30% on top of what our calculator shows). Real-world compound interest depends on the actual rate history, not a constant 7%.
The math itself is precise — standard amortization formulas, IEEE-754 floating point, verified against bank calculators. It's the model, not the calc, that requires judgment.
All finance calculators
- APR ↔ APY ConverterConvert between APR (nominal rate) and APY (effective yield) for any compounding frequency — daily, monthly, quarterly, annually, or continuous.
- Compound Interest CalculatorProject long-term investment growth with compound interest and regular contributions. Choose your compounding frequency and contribution timing.
- Discount CalculatorCalculate sale price and savings for any discount percentage. Includes common presets (10%, 20%, 30%, 50%, 75% off).
- Lease vs Buy CalculatorCompare total cost of leasing vs buying (car, equipment, appliances) over your chosen horizon. Includes financing, resale value, and money-down assumptions.
- Loan CalculatorCalculate monthly loan payments and total interest for any amount, rate, and term. See how much you save by adding extra payments.
- Mortgage CalculatorCalculate your monthly mortgage payment, total interest, and a year-by-year amortization schedule. All math runs in your browser.
- ROI CalculatorCalculate return on investment (ROI): total ROI percentage, net profit, and annualized ROI over any holding period. Useful for stocks, real estate, and business decisions.
- Sales Tax / VAT / GST CalculatorAdd tax to a net price OR reverse-calculate the pre-tax price from a gross total. Works for US sales tax, UK VAT, Singapore GST, and any custom rate.
- Simple Interest CalculatorCalculate simple interest on a loan or deposit. Enter principal, annual rate, and time (years, months, or days) — get interest earned and total balance.
Frequently asked
No — it shows principal and interest only. Real monthly cost typically adds 15-30% for property taxes, homeowner's insurance, PMI (if down payment < 20%), and HOA fees. Add those separately when planning your budget.
APR is the stated nominal rate without compounding. APY is what you actually earn or pay after compounding. 6% APR compounded monthly = 6.17% APY. Savings accounts advertise APY; credit cards advertise APR. Use our APR ↔ APY Converter to compare fairly.
On a $300,000 / 6.5% / 30-year mortgage, $100/month extra saves about $77,000 in interest and cuts the term to ~25 years. Our Loan Calculator shows the exact number for your loan.
Marginally. On a 7% rate over 30 years, monthly vs annual compounding differs by less than 1% of final balance. Daily vs monthly is basically noise. Focus on the RATE and CONTRIBUTION amount, not the frequency.
Depends heavily on the asset class and time horizon. Long-term stock market average is ~7-10% real return; treasury bonds 2-4%; savings accounts 0-5%; individual stock picks vary wildly. Our ROI Calculator shows total return and annualized CAGR side-by-side so you can compare.