Calculate loans, mortgages, compound interest, and ROI
Run the financial calculations that matter most: compound interest, loan amortization, investment growth, and retirement projections. Enter principal, rate, and time to see how your money grows or what your payments will look like over the life of a loan.
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You are considering a $20,000 loan at 5% APR over 5 years and need the monthly payment and total interest.
Loan
principal $20,000 · 5% APR · 60 monthly payments
Results
Monthly payment ≈ $377.42 Total paid ≈ $22,645 Total interest ≈ $2,645
It applies the standard amortisation formula (not simple interest), so the payment correctly accounts for the shrinking balance each month, the reason total interest is far less than 5% × $20,000 × 5. An amortisation schedule shows principal vs interest per payment.
Run the financial calculations that matter most: compound interest, loan amortization, investment growth, and retirement projections. Enter principal, rate, and time to see how your money grows or what your payments will look like over the life of a loan.
Compare monthly payments and total interest across different loan terms and rates.
Figure out how much to save monthly to reach a target amount by a specific date.
Model different return rates and contribution amounts to see long-term outcomes.
Generate an amortization schedule to understand how extra payments reduce total interest.
The compound interest module supports various compounding frequencies (daily, monthly, quarterly, annually) and can factor in regular contributions. Loan amortization generates a full payment schedule showing principal and interest breakdowns for each period. Investment projections model growth with reinvested returns, and retirement planning estimates how long savings will last given a withdrawal rate.
Daily, monthly, quarterly, semi-annually, and annually.
The projections show nominal returns. Adjust the interest rate downward to approximate real (inflation-adjusted) returns.
Yes. Enter a recurring contribution amount and frequency alongside the initial principal.
Every calculation runs locally in your browser. Your numbers and expressions are not transmitted or stored.