Personal Loan Calculator United Kingdom

This personal loan calculator works out the monthly repayment on a fixed-rate loan, with the total repaid and total interest, from your amount, APR and term.

What it does

The Personal Loan Calculator works out the fixed monthly repayment on an unsecured personal loan, along with the total you will repay over the term and the total interest cost, using standard amortisation.

Data sources & parameters

This calculator uses standard financial formulas and runs entirely in your browser. It needs no external rate data — your result is computed only from the values you enter above.

We always strive to use the latest data for every variable so our results and reports are as accurate as possible. Even so, errors are possible — you should not rely on this tool or its report alone, and we accept no liability for any decision made based on it.

The formula

monthly = loan × i ÷ (1 − (1 + i)^−n), where i = annual rate ÷ 12 and n = term in months; total repaid = monthly × n; interest = total repaid − loan

How it works

It turns your annual interest rate into a monthly rate, then applies the amortisation formula across the number of months you choose so every payment is identical and the balance reaches zero at the end of the term.

Where it is used

Comparing loan offers by their true monthly cost
Checking how the term changes total interest
Budgeting a fixed repayment before you apply

Worked example

Borrowing £10,000.00 at 7.9% over 36 months gives a monthly payment of …, … repaid in total and … of interest.

With a personal loan you borrow a fixed sum, agree a rate and a term, and repay the same amount every month until the balance is gone. This calculator applies the standard repayment formula to the amount, rate and term you enter and shows the monthly payment, the total you will repay and how much of that is interest.

How the monthly payment is worked out

The annual rate you enter is divided by twelve to give a monthly rate, and the payment is set so that the balance reaches zero in the final month. The payment stays level, but its make-up changes: in the first month most of it is interest on the full balance, and by the last month almost all of it repays the loan.

The formula is monthly payment = loan × i ÷ (1 − (1 + i) to the power of −n), where i is the monthly rate and n the number of months. At a zero rate it becomes the loan divided by the number of months, so a 0 percent promotional deal still gives a sensible payment.

Rate, APR and why they differ

The interest rate is the cost of the money itself. The APR also includes compulsory arrangement fees and expresses the total yearly cost, which makes it the fairer figure for comparing offers. Lenders quote a representative APR, meaning at least 51 percent of accepted applicants get that rate; others may be offered more. Enter the rate the lender actually quotes you.

How the term changes the cost

The term is the lever you control most. More months make each payment smaller, which can make an expensive loan look affordable, but interest builds up for longer and the total repaid rises. A shorter term raises the monthly payment and cuts the total interest. Running the same amount and rate over a few terms shows the trade-off between monthly affordability and total cost.

A worked example

You borrow £10,000 at 7.9 percent APR over 36 months. The payment is about £312.90 a month, about £11,264 repaid in total, so interest comes to about £1,264. Over 60 months the payment falls to about £202.29, but the interest rises to about £2,137, because the debt is outstanding for two more years.

How to use the calculator

Enter the amount you want to borrow, the APR the lender quotes and the term in months. The calculator shows the fixed monthly payment, the total you will repay and the total interest. The donut chart splits the total repaid into the loan and the interest on top.

Assumptions and limitations

This is a planning estimate. It assumes a fixed rate for the whole term, equal monthly payments and that the rate you enter is an annual rate divided by twelve, the usual convention for personal loans. It does not model separately charged arrangement fees, early repayment charges, payment holidays, missed payments, variable rates or add-ons such as insurance. Your actual APR depends on the lender’s assessment, so confirm the figures in the credit agreement before you sign.

About This Personal Loan Calculator

Use this personal loan calculator to get an instant estimate based on the figures you enter. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.

Frequently asked questions

How is the monthly payment on a personal loan calculated?

With the standard repayment formula. The annual rate is divided by 12 to get a monthly rate, and the payment is set so the balance reaches zero after the chosen number of months. Early payments are mostly interest and later ones mostly capital, but the payment stays the same each month.

What is the difference between the interest rate and the APR?

The interest rate is the cost of borrowing the money. The APR (annual percentage rate) also includes compulsory fees, so it reflects the total yearly cost. Lenders advertise a representative APR that at least 51 percent of accepted borrowers receive; your own rate can be higher depending on your credit record and the amount you borrow.

Does a longer loan term cost more?

Usually. Spreading the same loan over more months lowers each payment but means interest builds up for longer, so the total repaid and total interest both rise. A shorter term costs more each month but less overall.

Why does this calculator have no interest rate built in?

Personal loan rates vary by lender, amount and credit score, so there is no single official figure. Enter the APR the lender quotes you, and the tool applies the standard repayment formula to it.

What is the difference between a secured and an unsecured personal loan?

An unsecured loan is not tied to an asset, so approval and pricing depend on your creditworthiness and amounts are usually smaller. A secured loan is backed by property or another asset, which can mean larger sums or lower rates but puts that asset at risk if you cannot keep up repayments. This calculator models a standard fixed-rate unsecured loan.

About the author

Written and reviewed by

Taha Kheirandish

Economics student and independent researcher

Taha Kheirandish reads tax codes the way other people read maps — to find out where a system actually leads, not where it claims to go.

He is an economics student, and his work here is comparative by design. A pension deferral bonus in Quebec, a commuting allowance in Germany, a rent-increase ceiling in the Netherlands: each is a decision a government made about how money should move, and each reads differently once you set it beside eight others. He builds and checks these calculators across nine markets from primary sources — the regulation rather than a summary of it, the ministry’s own circular rather than a news item quoting it.

That is the editorial standard of the site as well as his habit. Every rate, threshold and bracket here carries the document it was read from and the date it takes effect, and gets re-checked when the law moves rather than when someone happens to notice.

He is a researcher, not a licensed adviser, and nothing on this site is personal financial advice. It is arithmetic done carefully with its sources shown — so that you can check it, and take it to someone who is.

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