01 / START WITH YOUR NUMBERS
How to use the loan calculator
This free loan repayment calculator estimates the monthly cost of a fixed-rate loan. You can change the amount, APR and term as often as you like, without entering personal details.
Choose the amount
Enter the amount you want to explore, from £100 to £100,000. These are calculator limits, not a statement of what you can borrow.
Add a term and APR
Choose one to ten years and enter an APR. If you have a quote, use its APR. Otherwise, experiment with different rates. The default 7.9% is illustrative and is not a current market rate or an offer.
Read the whole result
Check the monthly repayment, total interest and total to repay together. Then try a shorter or longer term using the comparison cards above.
You can use the calculator as a personal loan calculator where repayments are fixed and the balance is cleared over the term. It does not model credit cards, variable rates, payment holidays or a car finance balloon payment.
02 / THE NUMBERS IN PRACTICE
How much would a £10,000 loan cost?
At an illustrative 7.9% APR over five years, our calculator estimates £200.99 a month. The total to repay is £12,059.19, including £2,059.19 in interest.
| Term | Per month | Total interest | Total to repay |
|---|---|---|---|
| 3 years | £311.65 | £1,219.35 | £11,219.35 |
| 5 years | £200.99 | £2,059.19 | £12,059.19 |
| 7 years | £154.01 | £2,937.12 | £12,937.12 |
Fixed illustrations, separate from your entries above. Values are rounded for display; totals use unrounded payments.
In this example, seven years instead of three reduces the monthly payment by £157.64, but adds £1,717.77 to the total interest.
What if you borrow a different amount?
At the same APR and term, doubling the amount doubles the estimated repayment. So £20,000 over five years at 7.9% APR is £401.97 a month in this model. A real lender may offer different rates for different amounts, so check the quote rather than assuming the APR stays the same.
03 / GET TO KNOW THE RATE
APR and interest rates, explained
An interest rate describes the interest charged on borrowing. APR gives a broader annual cost measure that includes certain charges. An arrangement fee can therefore make the APR higher than the interest rate alone.
Representative APR is not a personal quote
An advertised representative APR must be offered at that rate or better to at least 51% of accepted applicants. Your own rate can be higher. Once you have a personal quote, enter that APR for a more relevant estimate.
Further reading: MoneyHelper’s guide to personal loans.
The 7.9% starting figure is an example.
It is here to show how the calculator works. It does not predict your eligibility, the rate you will get or the availability of a loan.
Why can a lender’s figure differ?
This calculator turns an effective annual rate into a monthly rate and assumes evenly spaced payments. A lender’s fees, payment dates and rounding can produce a different schedule. Use the lender’s figures when reviewing an actual offer.
04 / BEFORE YOU DECIDE
How to compare loan offers
Keep the amount and term the same when comparing costs. If one quote runs for longer, its lower monthly payment can hide a higher overall cost.
Monthly repayment
Put each payment alongside your regular outgoings. Consider whether there is still room for unexpected costs.
Total to repay
Compare the full amount paid over the term, not only the interest rate or headline monthly figure.
Fees and flexibility
Read the terms for arrangement fees, overpayments and early settlement. Ask what it would cost to clear the loan sooner.
Your actual offer
Check the personalised APR and repayment schedule. A calculator result cannot confirm that a lender will accept you.
Can I repay a personal loan early?
You can usually settle a personal loan early, but charges can apply. Ask the lender for a settlement figure and compare it with the payments you would otherwise make. This calculator does not estimate an early settlement balance. Citizens Advice explains early repayment.
05 / PLAIN ENGLISH, PLEASE
Your loan glossary
A few terms you will see in loan quotes and in your calculator results.
- APR
- Annual percentage rate. A yearly measure of borrowing costs, including interest and certain fees. It helps you compare offers, although your actual repayment schedule is still worth checking.
- Principal
- The amount you borrow before interest. In the calculator, this is the figure you enter in the loan amount field.
- Loan term
- The time allowed to repay the loan. Five years means 60 monthly payments in this calculator.
- Monthly repayment
- The amount paid each month. For the fixed-rate repayment loan modelled here, each payment covers interest and part of the amount borrowed.
- Total interest
- The cost of interest over the whole term. In our estimate, it is the total of all repayments minus the original loan amount.
- Total amount repayable
- Everything you pay back across the loan. Our calculator includes the borrowed amount and estimated interest, with no additional fees added separately.
- Fixed rate
- An interest rate that stays the same for an agreed period. This calculator assumes the rate stays fixed for the full term.
- Amortisation
- The gradual repayment of a balance. With each payment, the remaining balance falls. At a positive fixed rate, later payments usually repay more principal and less interest.
06 / BEHIND THE ESTIMATE
How loan repayments are calculated
The calculator uses an amortising repayment formula. This sets a regular payment that clears the original balance and interest by the end of the term.
Monthly repayment = P × r ÷ [1 − (1 + r)−n]
- P
- The amount borrowed
- r
- The monthly rate: (1 + APR ÷ 100)1/12 − 1
- n
- The number of monthly payments: years × 12
For a 0% APR, we simply divide the amount borrowed by the number of payments. Total interest is the sum of the unrounded payments minus the amount borrowed.
What the estimate assumes
You receive the full loan at the start, pay at the end of each month and keep the same rate throughout. There are no missed payments, extra repayments, separate fees or final lump sums. The calculator is a planning tool, not a lending decision or personalised financial advice.
Sources and further reading
The examples use Switcha’s calculator formula above. General borrowing information was checked against these sources on 10 September 2026.