Every calculator on this site runs instantly in your browser, shows the formula with your numbers, and needs no sign-up. Choose a category below.
Simple Interest Calculators
Flat interest on the original principal, for loans, notes and short-term deposits.
Compound Interest Calculators
Interest on interest, with daily, monthly, quarterly or annual compounding.
Compound Interest Calculator
Calculate compound interest and see how your money grows over time.
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Monthly Compound Interest Calculator
See how a balance grows when interest is added every month.
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Daily Compound Interest Calculator
Calculate growth with interest compounded every day (365 days per year).
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Quarterly Compound Interest Calculator
Calculate growth with interest compounded four times a year.
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Annual Compound Interest Calculator
Calculate growth with interest compounded once a year.
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Investment Calculators
Project long-term growth with regular contributions and inflation.
Savings Calculators
Plan how much to save and how long it takes to reach a goal.
Time Period Calculator
Find how long it takes for savings to grow to a target amount.
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Monthly Interest Calculator
Calculate how much interest a balance earns each month.
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Compound Interest Calculator with Regular Contributions
Add monthly, quarterly or annual deposits and choose whether they are made at the start or end of each period.
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Interest Rate Calculators
Work backwards to the rate, principal or time you need.
Which calculator should I use?
- Interest only on the original amount (most short loans and notes) → Simple Interest Calculator.
- Interest added to the balance (savings, deposits, investments) → Compound Interest Calculator.
- Saving a fixed amount regularly → Compound Interest with Regular Contributions.
- Solving for the unknown — rate, starting amount or time → Interest Rate, Principal or Time Period calculators.