Money Math Calculators
The arithmetic behind interest, loans and pricing — done exactly, with every step shown. You enter the numbers; the calculators do the math. They do not give financial advice.
Interest and savings
- Compound Interest CalculatorGrowth of a balance with any compounding frequency and optional monthly deposits.
- Simple Interest CalculatorInterest on a principal over years, months or days, with 365- or 360-day counting.
- APR to APY CalculatorConvert a nominal annual rate to the effective annual yield, and back.
- Savings Goal CalculatorHow much to set aside each month to reach a target amount by a deadline.
Loans
Business and pricing
For shoppers wanting a price with tax or a discount, see the everyday calculators.
What these calculators do — and don’t do
- They use your numbers only. There are no default “market” rates; every rate is one you type in.
- They show the formula and the working, so you can check each result by hand or in a spreadsheet.
- They leave out what they can’t know: fees, taxes, inflation, variable rates and product terms. A lender’s or bank’s official figures take precedence.
- They don’t recommend anything. For decisions about borrowing, saving or investing, talk to a qualified, independent adviser.
Rounding
Amounts are shown to 2 decimal places and work in any currency. Loan schedules round each month’s interest to the cent and adjust the final payment, as lenders do; interest and savings results are calculated at full precision and rounded only for display.