Repayment Calculator
Find the payment, term or affordable balance for a repayment plan.
About Repayment Calculator
A standard amortizing loan has four variables: principal, rate, term and payment. Know any three and this calculator finds the fourth. The 'affordable loan amount' mode is especially useful when you're shopping for a loan and want to know the maximum you can borrow given a monthly budget.
Formulas
Solve for payment (PMT)
Payment = Principal × r / (1 − (1+r)^−n)
- P
- Loan principal
- r
- Monthly rate
- n
- Months
- M
- Monthly payment
Solve for term (NPER)
n = −ln(1 − P·r/M) / ln(1+r)
Solve for affordable balance (PV)
Principal = Payment × (1 − (1+r)^−n) / r
Worked example
With the default values below, Repayment Calculator returns Monthly Payment of $470.05. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Solve Forone of Monthly Payment, Loan Term, Affordable Loan Amount
- Monthly Payment
- Annual Interest Rateaccepts 0–100 %
- 8 %
- Loan Amountaccepts 1–10,000,000 $
- 15,000 $
- Loan Termaccepts 1–600 months
- 36 months
- Target Monthly Paymentaccepts 1–1,000,000 $
- 500 $
Results
- Monthly Payment
- $470.05
- Total Interest Paid
- $1,921.64
- Total Amount Paid
- $16,921.64
Step by step
- 1Monthly rate= 0.6667%
- 2Payment (PMT)= $470.05
- 3Total interest= $1,921.64
Assumptions and limits
- The result is derived only from the 5 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax or fees or charges into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
- This is an estimate for general information and not professional financial, tax or legal advice. See the full disclaimer for the limits that apply to this kind of calculator.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How does 'affordable loan amount' help me?
Enter the maximum monthly payment you can afford, the expected rate and a term, and the calculator finds the largest loan that stays within your budget. For example, $500/month at 8% for 36 months supports a loan of about $16,000.
Can I use this for mortgages?
Yes, though the Mortgage Calculator gives a fuller picture with property taxes, insurance and PMI. This calculator handles the core principal-and-interest math for any fixed-rate, fully-amortizing loan.
What does the total interest tell me?
It's the total cost of borrowing: every dollar you pay above the original principal is interest. On a long-term loan, this often exceeds the principal itself.