Payment CalculatorFree online financial calculator — instant results, no sign-up
Monthly payment for a fixed term, or term for a fixed payment.
Estimates only, based on the inputs and assumptions shown. This is not financial, investment, tax, or legal advice. Prices, rates and local rules may change; crypto scenarios do not predict returns. Confirm important decisions with a qualified professional.
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How the result changes with loan amount
Each row below was calculated with this tool, keeping every other input at its default and changing only loan amount from half to one and a half times the default value. Use it to see how sensitive the answer is before you enter your own numbers.
| Loan amount ($) | Monthly payment | Total of payments | Total interest |
|---|---|---|---|
| 12,500 | $241.66 | $14,499.60 | $1,999.60 |
| 18,750 | $362.49 | $21,749.40 | $2,999.40 |
| 25,000 (default) | $483.32 | $28,999.20 | $3,999.20 |
| 31,250 | $604.15 | $36,249.00 | $4,999.00 |
| 37,500 | $724.98 | $43,498.80 | $5,998.80 |
About the Payment Calculator
This calculator determines the monthly payment and total borrowing cost for a fixed-rate loan over a set term. Alternatively, entering a target fixed payment calculates the exact number of months required to pay off the balance. It is designed for borrowers comparing loan terms or budgeting fixed monthly payoffs.
- Loan amount
- The initial principal balance borrowed, in dollars (e.g., 25,000).
- Rate
- The annual interest rate (APR) as a percentage (e.g., 6 for 6%).
- Term
- The repayment duration in months, used when calculating monthly payments (e.g., 60 for 5 years).
- Or fixed payment
- An optional target monthly payment amount in dollars; when set above 0, it overrides the term to calculate months to payoff.
Formula and method
When calculating payment: M = P × [r(1 + r)^n] / [(1 + r)^n − 1], Total Payments = M × n, Total Interest = Total Payments − P. When calculating payoff duration: n = −ln(1 − (P × r) / A) / ln(1 + r)
- PPrincipal loan balance
- rMonthly interest rate (Annual rate ÷ 100 ÷ 12)
- nNumber of monthly payments
- MCalculated fixed monthly payment
- AUser-specified fixed monthly payment
If a fixed payment greater than zero is provided, the tool solves for the required payoff months using the logarithmic amortization formula rounded to one decimal place. If the fixed payment is zero, it calculates the standard monthly payment using equal compounding periods, multiplying by the term to produce total payments and subtracting principal to find total interest.
Worked example
These are the calculator's starting values and the results it actually produces for them.
Inputs
- Loan amount25000 $
- Rate6 %
- Term60 months
- Or fixed payment0 $
Results
- Monthly payment$483.32
- Total of payments$28,999.20
- Total interest$3,999.20
How to use the Payment Calculator
- 1Enter the total principal amount borrowed in the Loan amount field.
- 2Input the annual interest rate as a percentage.
- 3Enter the desired term in months, or leave it and enter a target amount in Or fixed payment.
- 4Review the resulting monthly payment and total interest, or the calculated months to pay off the balance.
Reading your result
When solving for payment, the results display your required regular monthly payment, the cumulative amount paid over the entire life of the loan, and the total interest charge. When solving with a fixed payment, the output shows the exact number of monthly billing cycles required to reduce the principal balance to zero.
Limitations
The calculation assumes a constant interest rate and regular monthly payments without missed cycles, late fees, or prepayment penalties. It does not account for property taxes, insurance, origination fees, or daily interest accrual variations between leap years or differing month lengths.
Common questions
What happens if my fixed payment is smaller than the monthly interest?+
If your fixed payment is equal to or less than the monthly interest charge (P × r), the loan balance will never decrease, resulting in negative amortization where the formula cannot resolve to a finite payoff term.
Does this calculation match my mortgage or auto loan statement exactly?+
It matches the principal and interest amortization, but actual loan statements frequently include escrow fees, mortgage insurance, property taxes, or loan servicing fees not captured here.
How does extra monthly payment shorten my loan term?+
Any amount paid above the required amortized payment goes directly toward reducing the principal balance, which reduces subsequent interest accrual and cuts months off the back of the loan term.
Does the calculator save my information?+
Calculations run in your browser. While signed in, inputs and results are automatically recorded in account history; saving a result creates a separate saved record.
Further reading
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Results are estimates for informational purposes and are not financial, medical or legal advice.