Interest calculators reveal exactly how much your money grows — or costs — over time. Run the Compound Interest Calculator to watch returns build year over year, use the Simple Interest Calculator for straightforward loan estimates, check the Daily Interest Calculator for short-term costs, or discover what a credit card balance is really costing you each month with the Credit Card Interest Calculator.
Browse the Most Popular list to find the tools most savers and borrowers rely on, or switch to the Trending tab to see what is resonating this week. Every calculator is free, no login needed, and runs on any device.
- Tax Calculator
- Loan Calculator
- Interest Calculator
- Margin Calculator
- Salary Calculator
- Savings Calculator
- Payment Calculator
- Income Calculator
- Inflation Calculator
- Credit Card Calculator
- Deposit Calculator
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Future Value Calculator with ContributionsCalculate the future value of an investment with an initial principal plus regular monthly, quarterly or annual contributions and compound interest.
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Present & Future Value Algebra CalculatorSolve for present value or future value using FV = PV(1+r)ⁿ. Enter amount, rate per period, and number of periods to get instant results.
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Solve Compound Interest for Rate or TimeSolve the compound interest formula for the unknown interest rate or time. Enter principal, future amount and compounding frequency to find r or t.
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Effective Annual Rate (APY) CalculatorConvert a nominal annual interest rate into the effective annual rate (APY) using the compounding formula APY = (1 + r/n)^n − 1.
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Continuous Compound Interest CalculatorCalculate continuous compound interest with the formula A = Pe^(rt). Find the future value and total interest from principal, rate, and time instantly.
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Simple Interest Percentage (Rate) CalculatorFind the simple interest rate as a percentage from principal, interest earned, and time. Rate = (I / (P x T)) x 100. Free, instant, accurate.
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Annualized Return (CAGR) on Deposit CalculatorCalculate the annualized return (CAGR) of a deposit or investment from its start value, end value and holding period. Free and instant.
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After-Tax Savings Interest CalculatorCalculate the net interest you keep on savings after tax. Enter principal, rate, compounding and tax rate to see gross interest, tax owed and final balance.
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How Much Can I Borrow From a Monthly Payment?Find out how much you can borrow based on a monthly payment, interest rate, and term. Reverse loan calculator using present value of an annuity.
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Zero-Coupon Bond Price CalculatorCalculate the present value (price) of a zero-coupon bond from its face value, yield, years to maturity and compounding frequency.
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ACB Savings Doubling Time CalculatorFind how many years it takes to double your savings at a given annual interest rate using the exact ln(2)/ln(1+r) formula and the Rule of 72.
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Time to Double Your Deposit CalculatorFind out how many years it takes to double your deposit at a given interest rate and compounding frequency using the exact compound-interest formula.
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How Much Interest Will I Earn CalculatorFind out how much interest you'll earn on any amount with compound interest. Enter principal, rate, term and compounding frequency to see total interest.
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Monthly Payment from APR CalculatorCalculate your fixed monthly loan payment from the loan amount, APR, and term in months. See total interest and total of payments instantly.
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Effective Annual Rate (EAR) CalculatorConvert a nominal APR into the effective annual rate (EAR) using EAR = (1 + APR/m)^m − 1. Compare monthly, daily, quarterly compounding instantly.
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Simple Interest Loan Payoff CalculatorCalculate the total payoff amount on a simple-interest loan. Enter your principal, annual rate, and days to see accrued interest and what you owe.
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Money Doubling Time CalculatorFind how many years it takes to double your money at a given interest rate using the Rule of 72 plus the exact logarithmic formula.
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Interest vs Principal Payment Split CalculatorSplit a single loan payment into interest and principal. Enter your balance, rate, and payment to see exactly how much reduces your debt.
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Gross-Up Interest CalculatorCalculate the taxable-equivalent (pre-tax) yield of a tax-free investment. Enter your tax-free yield and marginal tax rate to gross up the interest.
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Loan Total Interest Calculator (Amortized)Calculate the total interest paid on an amortized loan from the amount, annual rate, and term. Also shows monthly payment and total of payments.
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Mortgage Discount Points Break-Even CalculatorFind how many months it takes to recoup the cost of mortgage discount points. Compare rates, see monthly savings, and decide if buying points pays off.
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Flexi Fixed Deposit CalculatorCalculate the maturity value and interest of a flexi fixed deposit with quarterly compounding. Enter principal, annual rate and term to see returns.
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Monthly Interest Earned CalculatorCalculate how much interest your savings earn per month from your balance and annual interest rate. Free, instant monthly interest calculator.
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Total Cost of Loan CalculatorCalculate the total cost of a loan — principal plus all interest paid. Enter amount, rate and term to see monthly payment and lifetime cost.
Frequently asked questions
What is the difference between simple and compound interest, and can I calculate both here?
Simple interest is applied only to the original principal; compound interest grows on accumulated interest too, making balances expand faster over time. Both are covered — the Simple Interest Calculator handles straightforward scenarios, while the Compound Interest and Reverse Compound Interest calculators model long-term growth.
How accurate are these interest calculators?
All tools apply standard, well-established interest formulas. Results are accurate estimates for financial planning. These calculators are not financial advice — actual rates and fees vary by lender and product. Consult a qualified financial professional before making significant borrowing or investment decisions.
Are the calculators free?
Yes. Every interest calculator on this page is free with no account needed. Enter your principal, rate, and time period — results appear instantly on any phone, tablet, or computer.
Do you store my financial inputs?
No. All calculations happen locally in your browser. Your principal amounts, interest rates, and personal finance data are never transmitted to or stored on our servers.
Which interest calculators do people use most?
The default list ranks tools by real-world usage. The Compound Interest Calculator and Loan Interest Calculator consistently appear near the top. Use the Trending tab to see which tools are gaining the most traction right now.
