Repayment Calculator
Calculate the periodic repayment installment for a fixed-rate balance, given the principal, annual interest rate, repayment term, and frequency.
Calculator Inputs
Sets the currency this calculator's numbers are denominated in. This is presentation only — it does NOT convert your numbers between currencies, it only changes how they're formatted.
The balance you're repaying.
The nominal annual interest rate (e.g. 7.5 for 7.5%), fixed for the full term.
How many years (and months) you have to repay the balance. The number of payments is derived from this and your chosen frequency.
Additional months (0-11). For 18 months, enter 1 year 6 months.
How often you make repayments.
- Periodic Repayment
- $400.76
- Frequency
- Repayment frequency: Monthly
- Total of All Repayments
- $24,045.51
- Total Interest Paid
- $4,045.51
About these results
CalcSpectrum calculators produce automated estimates using established formulas and the specific values you enter. Because real-world outcomes depend on input accuracy, mathematical assumptions, and rounding conventions, please verify critical figures with an appropriately qualified financial, tax, medical, legal, or other professional, as relevant.
Financial Notice: These figures are informational estimates for personal planning only. They do not constitute financial, investment, tax, or legal advice, nor do they represent a lending offer or credit approval. Provider and financial institution figures, rates, fees, and underwriting requirements may differ.
How It's Calculated
Formula
This calculator answers a simple question: what regular payment repays a given balance, at a fixed annual rate, over a chosen term? Enter the principal, the annual fixed interest rate, how many years you have to repay it, and how often you'll make repayments, and it returns the periodic installment. The number of payments is derived automatically from your term and frequency — if you already know the exact number of payments instead of a term in years, use Payment Calculator, which takes that number directly. This calculator computes a fixed regular installment only — it does not model extra payments or payoff acceleration; for that, see Mortgage Payoff Calculator.
Worked Examples
Monthly repayment: $20,000 principal, 7.5% annual rate, 5-year term
- paymentsPerYear = 12 (monthly), so n = 5 × 12 = 60 payments
- periodicRate r = 0.075 / 12 = 0.00625
- Repayment = 20000 × 0.00625 × (1.00625)^60 / ((1.00625)^60 − 1) ≈ $400.76
Biweekly repayment: $15,000 principal, 6% annual rate, 3-year term
- paymentsPerYear = 26 (biweekly), so n = 3 × 26 = 78 payments
- periodicRate r = 0.06 / 26 ≈ 0.0023077
- Repayment = 15000 × r × (1 + r)^78 / ((1 + r)^78 − 1) ≈ $210.36
Frequently Asked Questions
How is this different from Payment Calculator?
This calculator asks for a repayment term in years and derives the number of payments for you. Payment Calculator instead asks for the exact number of payments directly. Use whichever matches what you actually know — a term in years, or an exact payment count.
Does this account for extra payments or early payoff?
No — this calculator computes a single fixed regular installment for the full term as scheduled. For modeling extra payments and how they shorten a payoff, see Mortgage Payoff Calculator.
Why does my biweekly repayment look smaller than half my monthly repayment would be?
A biweekly schedule makes 26 payments a year, not 24 — there are slightly more than 52 weeks in a year, so 26 fortnights. Making more, smaller payments more often also pays down principal faster, so the biweekly installment ends up smaller than simply halving the monthly figure.
What happens if I enter a 0% interest rate?
The repayment becomes a straight-line division of the principal across the number of payments, with $0 total interest — a valid boundary case, not an error.