Repayment Calculator

Estimate repayments, total interest, and total cost for loans using fixed-rate repayment inputs.

How to Use

  1. Enter the loan amount, interest rate, and loan term.
  2. Select the repayment frequency and optional extra payment amount.
  3. Choose whether the rate is nominal APR with compound periods or a simple annual percentage input.
  4. Review the repayment summary, amortization preview, and Show Work steps.
Loan Snapshot

Repayment Overview

Fixed-payment estimates for common loan planning and budgeting scenarios.

Payment
—
Total Interest
—
Total Repaid
—
Payoff Time
—
Interest Share —

Visual split between principal and interest across the full repayment period.

Principal
—
Rate / Period
—
Payments
—
Inputs & Settings
Enter loan details to calculate repayment amount and total borrowing cost.
Enter the original borrowed amount before interest.
Annual interest rate as a percentage.
Whole or partial years are allowed.
Optional extra months beyond full years.
Choose how often payments are made.
Used when converting APR into periodic rate.
Optional additional amount added to each payment period.
Optional for payoff date and amortization preview rows.
Show Work (step-by-step)
—
Work should show periodic rate conversion, payment formula inputs, total repayment, and interest totals.

Repayment Formula

Quick answer: For a standard fixed-rate repayment loan, payment is commonly calculated with the annuity formula.

This tool is intended for standard repayment planning, budgeting, and payoff comparisons.

  • Periodic rate: r = annual rate / periods per year
  • Number of payments: n = years × payments per year (+ extra months converted)
  • Payment: P = L × r / (1 − (1 + r)^−n)
  • Total repaid: payment × number of payments
  • Total interest: total repaid − principal
Where L = loan amount, r = periodic interest rate, and n = number of payment periods.

Amortization Preview

A short preview of the repayment schedule. Full generation happens in the tool script.

# Date Payment Principal Interest Balance
Enter loan details to preview the amortization schedule.

FAQ

What does this repayment calculator estimate?

It estimates the periodic payment, total interest, total amount repaid, and a basic amortization breakdown for fixed-rate loans.

Does extra payment reduce the loan term?

Yes, when enabled, extra payment per period can reduce payoff time and total interest. Exact results depend on the repayment model used in the script.

What repayment frequencies are supported?

This page is designed for monthly, fortnightly, and weekly repayment modes.

Is this a quote or lender approval?

No. It is a planning tool and should not replace official lender disclosures, contracts, or amortization statements.

Tool Info

Last updated:

Updates may include repayment mode refinements, amortization display improvements, and edge-case handling.