Loan Amortization Calculator
Generate a month-by-month loan amortization schedule with principal, interest, balance, and yearly totals.
Loan details
Enter the loan amount, interest rate, term, optional start month, and any extra monthly payment.
Currency
Principal amount borrowed.
Fixed annual rate. Use 0 for an interest-free loan.
Optional. Added to principal each month.
Whole years in the term.
Optional extra months added to the term.
Optional. Sets the dates shown in the schedule.
Monthly payment
£1,498.88
Scheduled principal and interest, before any extra payment.
Total interest
£289,595.47
Estimated interest paid over the life of the loan.
Total repayment
£539,595.47
Principal plus total interest.
Number of payments
360
Months until the balance reaches zero.
Payoff date
Dec 2055
Estimated month of the final payment.
Loan term
360 months
Total scheduled payments at the start of the loan.
Amortization schedule
Payment-by-payment breakdown
See how each payment splits between principal and interest, how interest accumulates, and how the balance falls to zero.
| # | Date | Payment | Principal | Interest | Balance | Cumulative interest |
|---|---|---|---|---|---|---|
| 1 | Jan 2026 | £1,498.88 | £248.88 | £1,250.00 | £249,751.12 | £1,250.00 |
| 2 | Feb 2026 | £1,498.88 | £250.12 | £1,248.76 | £249,501.00 | £2,498.76 |
| 3 | Mar 2026 | £1,498.88 | £251.37 | £1,247.51 | £249,249.63 | £3,746.26 |
| 4 | Apr 2026 | £1,498.88 | £252.63 | £1,246.25 | £248,997.00 | £4,992.51 |
| 5 | May 2026 | £1,498.88 | £253.89 | £1,244.99 | £248,743.11 | £6,237.49 |
| 6 | Jun 2026 | £1,498.88 | £255.16 | £1,243.72 | £248,487.95 | £7,481.21 |
| 7 | Jul 2026 | £1,498.88 | £256.44 | £1,242.44 | £248,231.51 | £8,723.65 |
| 8 | Aug 2026 | £1,498.88 | £257.72 | £1,241.16 | £247,973.80 | £9,964.81 |
| 9 | Sept 2026 | £1,498.88 | £259.01 | £1,239.87 | £247,714.79 | £11,204.68 |
| 10 | Oct 2026 | £1,498.88 | £260.30 | £1,238.57 | £247,454.49 | £12,443.25 |
| 11 | Nov 2026 | £1,498.88 | £261.60 | £1,237.27 | £247,192.88 | £13,680.52 |
| 12 | Dec 2026 | £1,498.88 | £262.91 | £1,235.96 | £246,929.97 | £14,916.49 |
The schedule shows principal and interest only. The last payment is capped so the balance reaches zero without overpaying.
Interpretation
What your schedule shows
Monthly payment
Your estimated monthly payment is £1,498.88 in principal and interest.
Interest over time
Total interest is estimated at £289,595.47 across 360 payments.
Principal vs interest
Early payments are interest-heavy because interest is charged on the larger opening balance. The principal share grows each month.
Extra payments
Add an optional extra monthly payment to see how much interest and time you could save.
Formula
How the schedule is built
Monthly payment
Payment = P × r × (1 + r)^n / ((1 + r)^n − 1)P is the loan amount, r is the monthly rate (annual rate ÷ 12), and n is the number of months. At 0% the payment is simply P ÷ n.
Monthly interest
Interest = Remaining balance × rEach month interest is charged on the balance still owed, so it falls as the balance drops.
Principal each month
Principal = Payment − Interest (+ extra)Whatever is left of the payment after interest reduces the balance. Any extra payment is added straight to principal.
Examples
Worked examples
Standard loan
A 10,000 loan at 6% over 5 years has a payment near 193.33 per month, 60 payments, and ends at a zero balance.
Zero interest
A 12,000 loan at 0% over 1 year is just 1,000 per month with no interest, so total repayment equals the amount borrowed.
Extra payment
Adding a small extra amount each month to that 5-year loan pays it off before month 60 and lowers the total interest.
Loan basics
Key terms
Principal
The amount borrowed before any interest or extra payments are applied.
Interest rate
The annual rate, divided by 12, sets how much interest accrues each month.
Term
The number of months over which the loan is repaid in equal scheduled payments.
Cumulative interest
A running total of interest paid so far, useful for seeing the true cost over time.
Trust
About this estimate
Transparent method
Uses the standard fixed-rate amortization formula so you can follow exactly how each payment is split.
Schedule focused
Built around the month-by-month schedule, payment dates, cumulative interest, and yearly totals.
Estimate only
Results are estimates. Actual fees, compounding, escrow, taxes, insurance, and lender rules may change real figures.
FAQ
Loan amortization questions
Loan amortization is the process of paying down a loan over time through scheduled payments. Each payment is split between interest on the outstanding balance and principal that reduces what you still owe, until the balance reaches zero.
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Estimate only. This calculator is for general planning and education, not financial, tax, investment, legal, lender, or professional advice. Actual results can vary based on rates, fees, taxes, market conditions, lender rules, employer rules, contribution limits, and local regulations. Verify important decisions with a qualified professional, lender, official source, or relevant institution.
Related reading
Learn the formula, assumptions, examples, or context behind this tool.