Loan Repayment Calculator — Monthly Payment & Total Interest
Find your exact monthly repayment on any fixed-rate loan — mortgage, personal loan or auto finance — plus the total cost and principal-versus-interest split over the full term.
%
years
Fixed payment due each month for the full loan term
405,124.3
total repaidPrincipal
49.4%
Total interest
50.6%
- 1
Monthly interest rate
r = 6.5% ÷ 12 ÷ 100 = 0.005417 - 2
Number of payments
n = 25 × 12 = 300 - 3
Growth factor
(1 + 0.005417)ⁿ = 5.0562Compound growth of the loan balance over the full term at the monthly rate. - 4
Monthly repayment
200,000 × 0.005417 × 5.0562 ÷ (5.0562 − 1) = 1,350.41
How does this calculator work?
Monthly repayment = L × [r(1+r)^n] / [(1+r)^n − 1], where L is the loan amount, r the monthly interest rate and n the number of monthly payments. Enter the loan, annual rate and term in years to get the monthly payment, total repaid and how much of that is interest.
Formula
How this is calculated
A fixed-rate loan is repaid in equal monthly instalments called an annuity. Each payment covers the interest accrued on the remaining balance that month plus a slice of the principal. Early in the loan most of each payment is interest; as the outstanding balance falls, the principal share grows — this gradual shift is called amortisation.
The standard annuity formula M = L × [r(1+r)^n] / [(1+r)^n − 1] gives the fixed monthly payment where L is the loan amount, r is the monthly interest rate (annual rate divided by 12), and n is the total number of monthly payments (years × 12). Multiplying M by n gives the total repaid; subtracting the original loan gives the total interest cost.
This calculator assumes a level-payment, interest-compounding-monthly structure typical of mortgages and most consumer loans. It does not account for lender arrangement fees, mortgage insurance, variable-rate changes, offset accounts or early-repayment charges. Always verify the figure with your lender's official amortisation schedule.
Frequently asked questions
Shortening the loan term is the most powerful lever — cutting the term roughly halves the interest. Making extra repayments reduces the outstanding balance and the interest charged on it. Securing a lower interest rate through remortgaging or negotiating also helps materially over a long term.
A repayment (capital-and-interest) mortgage pays down both principal and interest each month, so the balance reaches zero at the end of the term. An interest-only mortgage pays only the monthly interest — the original loan balance is still owed in full at the end and must be repaid from savings, investments or by selling the property.
Lenders may charge interest from the exact drawdown date, use daily rather than monthly compounding, bundle mortgage protection insurance or arrangement fees into the payment, or apply a different rounding convention. Treat this calculator as a close estimate and confirm the precise schedule with your lender.
Also known as
TG we-Calculate Editorial Team. (2026). Loan Repayment Calculator — Monthly Payment & Total Interest [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/loan-repayment-calculator
TG we-Calculate Editorial Team. "Loan Repayment Calculator — Monthly Payment & Total Interest." TG we-Calculate. 2026. https://we-calculate.com/calculator/loan-repayment-calculator.
TG we-Calculate Editorial Team, "Loan Repayment Calculator — Monthly Payment & Total Interest," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/loan-repayment-calculator
@misc{wecalculate_loan_repayment_calculator, title = {Loan Repayment Calculator — Monthly Payment & Total Interest}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/loan-repayment-calculator}}, year = {2026}, note = {TG we-Calculate} }
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