Finance tools
Personal loan overpayment calculator.
See how extra monthly payments could change the interest and time left on an existing loan. Or use an amount and term to estimate repayments for a new loan.
Your repayment estimate
Add your loan details
Enter your loan details to compare repayments with and without extra monthly payments.
- Balance over time
- Interest and time to repay
- Monthly and yearly repayment schedules
Estimates use a fixed nominal rate and exclude fees.
Monthly payment
£454.57
£404.57 regular + £50.00 extra
Total interest
£3,692.35
Over the full repayment period
Total repaid
£23,692.35
Loan amount + interest
52 monthly payments of £454.57, then a final payment of £54.71.
Projected payoff
7 months earlier
53 months (4 years, 5 months) instead of 60 months (5 years)
Estimated interest avoided
£581.95
Before charges, compared with no overpayments
Your balance over time
See how your balance falls with and without overpayments.
- With overpayments
- No overpayments
- Principal paid
- Interest charged
Fixed nominal rate, no fees and payments at month end. The first payment is after one model month. Daily interest, actual payment dates and lender rules can change the result. These estimates are not lender settlement quotations or personalised advice.
Repayment breakdown
Where your payments go
As you pay down the loan, less of each payment goes towards interest and more pays off the amount you borrowed.
Annual breakdown
| Year | Payments | Principal repaidPrincipal | Interest paidInterest | Remaining balanceBalance |
|---|---|---|---|---|
| 1 | £5,454.84 | £4,018.27 | £1,436.57 | £15,981.73 |
| 2 | £5,454.84 | £4,347.46 | £1,107.38 | £11,634.27 |
| 3 | £5,454.84 | £4,703.62 | £751.22 | £6,930.65 |
| 4 | £5,454.84 | £5,088.96 | £365.88 | £1,841.69 |
| 5 | £1,872.99 | £1,841.69 | £31.30 | £0.00 |
The final year has 5 payments. Final payment: £54.71. Figures are rounded to the nearest penny.
Overpaying your loan
Could you pay off
your loan sooner?
Paying an extra £50.00 a month reduces your balance faster, so you pay less interest. In this example, you’d clear the loan seven months sooner.
Spreading repayments over a longer term can lower the monthly payment, but you may pay more interest overall. Try a few amounts and terms to see what fits your budget.
Check your lender’s overpayment rules and any early repayment charges before changing your payments.
| No overpayments | With £50.00 extra | |
|---|---|---|
| Monthly payment | £404.57 | £454.57 |
| Final payment | £404.67 | £54.71 |
| Time to repay | 60 months (5 years) | 53 months (4 years, 5 months) |
| Total interest | £4,274.30 | £3,692.35 |
£581.95 estimated interest avoided before charges
Common questions
Loan calculator FAQs
What do I need for an existing personal loan?
Choose Existing loan and enter the current principal balance, your contractual monthly repayment and the nominal annual interest rate. Principal is the amount still owed excluding future interest. A statement balance or settlement figure may contain interest, fees or other amounts, so do not assume it is principal. Ask your lender to confirm the figures.
If you cannot obtain the principal balance and nominal rate, this model cannot give a reliable estimate for your loan. Ask your lender for an overpayment illustration instead. Lender tools such as the Lloyds loan overpayment calculator and Halifax loan calculator use APR. This calculator does not convert APR or reproduce their estimates.
How are monthly loan repayments calculated?
In Amount and term mode, your monthly repayment depends on how much you borrow, the annual interest rate and the loan term. Payments are made at the end of each month, with interest charged on the opening balance. Regular payments stay the same; the final payment clears what remains. Overpayments go on top of your regular payment and shorten the term.
Divide the nominal annual interest rate, expressed as a percentage, by 100, then by 12 to get the monthly rate. For example, 12% a year gives a monthly rate of 0.01. For a loan amount P, monthly rate r greater than zero and n monthly payments, the monthly repayment M is:
At 0% interest, use M = P ÷ n. The calculator rounds regular payments to the nearest penny, with half-pennies rounded up, and adjusts the final payment to clear the balance. It carries fractions of a penny in the balance until settlement. The displayed principal and interest add up to each payment. For small loans or long terms, payment rounding can change the payoff month or final payment substantially.
Existing loan mode uses your contractual repayment in pounds and pence. Each month, interest is the exact opening principal balance multiplied by the nominal annual percentage divided by 1,200. The closing balance is the opening balance plus that interest, less the contractual repayment and monthly extra. Interest and carried balances are not rounded monthly. Settlement is rounded to the nearest penny, with half-pennies rounded up. Displayed principal is the difference between rounded opening and closing balances; displayed interest is the payment minus that principal.
Both plans start from the current principal. The baseline has no extra payments and must clear within 600 model months (50 years). If it cannot, or the contractual payment does not reduce principal, the calculator asks you to check the figures with your lender. It does not add a balloon payment at the limit. Durations are model months and years, not calendar payoff dates.
For example, £100 at 12% nominal interest has a monthly rate of 1%. With a £60 contractual repayment, you pay £60 then £41.41, including £1.41 interest. Adding £10 monthly changes those payments to £70 and £31.31. Estimated interest avoided is £0.10 before charges; both plans take two months.
Is the annual interest rate the same as APR?
APR is an annual measure of the cost of borrowing and can include fees. It may differ from the annual interest rate charged on your balance. Use the nominal annual interest rate from your loan agreement. If it is not clearly stated, ask your lender. Do not substitute APR.
How much could I save by overpaying a loan?
It depends on the balance, interest rate and time left to repay. Use this loan overpayment calculator to compare the interest and repayment term with and without extra monthly payments. The estimate assumes your lender applies each overpayment to the balance and keeps your regular payment the same. Check any overpayment limits or charges with your lender.
Can I use this as a car loan calculator?
You can estimate a fixed-rate personal loan used to buy a car, with equal monthly repayments and no balloon payment. PCP, hire purchase fees, variable rates and balloon payments need a calculation that includes those terms. This tool does not model them.
What happens if the interest rate is 0%?
Amount and term mode divides the amount borrowed by the number of monthly payments. Existing loan mode uses the contractual repayment you enter. You pay no interest, so overpayments reduce the time to repay without saving interest. The final payment is adjusted for rounding.
Are fees and early repayment charges included?
No. This calculator excludes arrangement fees, insurance, late-payment fees and early repayment charges. It assumes monthly payments made on time and a fixed rate for the whole term. Daily interest, payment dates and your lender’s rounding rules may change the figures. The model also excludes repayment holidays, mortgage-specific rules and income-contingent student loans. Results are estimates, not lender settlement quotations, a loan offer or personalised advice.
Check your agreement for early repayment charges. If you want to repay in full, ask your lender for a settlement statement, as explained in MoneyHelper’s personal loan guidance. Interest avoided here is estimated before those charges.
