The most useful number in any personal loan decision is the total amount repayable, not the monthly payment and not the APR in isolation. The total shows what the loan actually costs: the amount borrowed plus the interest over the full term. This calculator makes that number visible for any combination of amount, rate, and term, with a term comparison table that shows all seven common terms at once so the trade-off between monthly affordability and total cost is clear before a decision is made.
All figures are illustrative. The APR slider shows an illustrative rate for modelling purposes. The rate offered to any individual depends on their credit profile, income, existing commitments, and the lender’s own criteria. The advertised representative APR is only guaranteed to 51% of accepted applicants. This tool is for informational purposes and does not constitute financial advice.
At a Glance
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Adjust three inputs to see the monthly payment, total cost, and total interest instantly. The calculation updates as you move each slider.
The calculator uses the standard reducing-balance formula that UK lenders apply. Monthly interest is charged on the outstanding balance, which decreases with every payment. The result is the same figure a lender would calculate for the same inputs, though the rate offered to any individual may differ from the illustrative APR shown.
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The term comparison table shows all terms from 1 to 7 years simultaneously. This is the output most people find most useful.
Instead of adjusting the term slider back and forth, the table shows the monthly payment, total repaid, total interest, and interest as a percentage of the amount borrowed for every term at once. The selected term is highlighted, but all seven are visible. Clicking any row updates the main result to that term. This makes the cost of a longer term visible at a glance.
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The APR you enter is illustrative. The rate you are offered depends on your credit profile and the lender’s criteria. Use the slider to model different scenarios.
Personal loan APRs for mainstream borrowers typically range from 3% to 30%, depending on credit profile, income, and the amount borrowed. The lowest rates are generally available in the £7,500 to £15,000 range. Modelling at different APRs shows how sensitive the total cost is to the rate, which is useful for understanding what a higher-than-expected rate would actually cost.
Personal Loan Repayment Calculator
Enter the amount, an illustrative APR, and the term. All figures are illustrative and do not represent any specific lender.
Monthly payment
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Total repaid
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Total interest
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Term comparison
All terms at your selected amount and APR. Click a row to select it.
| Term | Monthly | Total repaid | Interest | Interest % |
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About this calculator
Whether you are in early research or comparing a specific offer, this calculator shows the monthly payment and total cost for any combination of amount, rate, and term.
Uses the standard reducing-balance formula that UK lenders apply. The term comparison table shows all seven common terms simultaneously so the trade-off is visible without adjusting the slider.
Use it to check what a loan would cost at different amounts and terms, to verify a lender’s quote, or to compare the total cost of two offers at different rates.
The APR slider is illustrative. The rate any individual is offered depends on their credit profile, income, and the lender’s own criteria. Use soft-search eligibility checkers to see your likely personal rate.
How to use this calculator
Move the slider or type the amount you want to borrow. The range covers £1,000 to £25,000, which is the standard range for mainstream personal loans. If you need more than £25,000, a secured loan may be the more appropriate product.
Choose an APR to model. If you do not know what rate you are likely to be offered, 7% is a reasonable starting point for a borrower with a good credit profile. Model at 10% to 15% for a more conservative scenario, or at 5% for the most competitive end of the market.
Move the term slider to see the monthly payment and total cost for a specific term, or use the term comparison table to see all seven terms simultaneously. Clicking any row in the table updates the main result. The table is the quickest way to find the shortest affordable term.
The monthly payment shows affordability. The total shows cost. A lower monthly payment on a longer term costs more in total. The interest-as-percentage figure shows how much the borrowing adds to the price of what you are buying. Both numbers matter.
Understanding the numbers
The calculator produces four outputs, each answering a different question. The monthly payment is the fixed amount collected by direct debit each month for the full term. It answers the question: can I afford this? The total repaid is the monthly payment multiplied by the number of months. It answers: what does this loan actually cost? The total interest is the difference between the total repaid and the amount borrowed. It answers: how much am I paying for the privilege of having the money now? The interest as a percentage of the amount borrowed answers: how much is the borrowing adding to the price of what I am buying?
The term comparison table is designed to make the trade-off between monthly affordability and total cost visible in a single view. On a £10,000 loan at an illustrative 7% APR, the monthly payment drops from £861 over one year to £142 over seven years. The total interest increases from £337 to £1,965 over the same range. The table shows both figures for every term simultaneously, so the borrower can find the shortest term where the monthly payment fits the budget, knowing exactly what each additional year of term adds to the total cost.
The principal-to-interest bar provides a visual representation of where the money goes. On shorter terms, the bar is predominantly principal (repaying what was borrowed) with a small interest segment. On longer terms, the interest segment grows. This visual cue reinforces the numerical trade-off shown in the table.
How the APR affects the total cost
The APR (annual percentage rate) is the annualised cost of borrowing, including any compulsory fees. For most personal loans, there are no compulsory fees, so the APR and the interest rate are effectively the same. The APR determines how much interest accrues on the outstanding balance each month, which in turn determines the monthly payment and the total cost.
The sensitivity of the total cost to the APR increases with the term. On a £10,000 loan over one year, the difference between 5% and 10% APR is approximately £130 in total interest. On the same loan over five years, the difference is approximately £700. This is because the higher rate applies to a balance that is outstanding for more months, and the compounding effect magnifies the gap. The guide to understanding APR on personal loans covers the mechanics in full, including the representative APR system and why the advertised rate is not guaranteed.
For borrowers who do not know what APR they are likely to be offered, running the calculator at two or three different rates (a best-case, a mid-case, and a conservative case) shows the range of possible outcomes. This is particularly useful for borrowers whose credit profile falls in the fair-to-good range, where the gap between the advertised rate and the personal rate can be significant. The representative APR reality checker models this gap specifically.
Related tools
A visual explorer showing the cost curve across all terms. Companion to this calculator for understanding the term trade-off.
Compare up to three loan offers side by side on monthly payment, total interest, and total cost.
See how the gap between the advertised rate and a realistic personal rate affects the monthly payment and total cost.
Looking for more loan resources?
Guides and tools covering secured loans, debt consolidation, and home improvementsFrequently asked questions
What APR should I use in the calculator?
If you do not know what rate you are likely to be offered, 7% is a reasonable starting point for a borrower with a good credit profile borrowing in the £7,500 to £15,000 range. For smaller amounts (under £5,000), rates tend to be higher; modelling at 10% to 15% gives a more realistic picture. For borrowers with excellent credit profiles, rates as low as 3% to 5% may be available on competitive products.
The most useful approach is to model at three rates: an optimistic case (the representative APR of the best-known lender), a realistic case (two to three percentage points above the representative APR), and a conservative case (five to six percentage points above). This gives a range of total costs and shows how sensitive the decision is to the rate. The guide to what credit score you need covers how different score bands typically translate into different rates.
Why does the total cost increase so much with a longer term?
Interest is charged on the outstanding balance each month. On a longer term, the balance decreases more slowly because the monthly payments are smaller. This means interest accrues on a higher balance for more months. The combination of a higher average balance and more months of charging produces a significantly higher total interest cost, even though the monthly payment is lower.
On a £10,000 loan at 7% APR, the total interest over two years is approximately £745. Over five years, it is approximately £1,887. The five-year term more than doubles the interest cost, even though the APR is identical. The term comparison table in the calculator shows this effect for every term at once, which is why it is the most useful output for deciding how long to borrow.
Is the monthly payment figure exact?
The monthly payment is calculated using the standard reducing-balance annuity formula, which is the same method UK lenders use. For the same inputs (amount, APR, and term), the calculator will produce the same monthly figure as the lender’s own calculator. The difference arises from the APR: the illustrative rate entered in this calculator may not match the rate the lender would offer, which is determined by the borrower’s individual circumstances.
If a lender has already quoted a specific rate, entering that rate into this calculator will verify the monthly payment and total cost. If the figures do not match, it may be because the lender’s APR includes a fee that this calculator does not account for, or because the lender calculates interest slightly differently (daily vs monthly compounding). For most mainstream personal loans, the figures will be very close.
What is the term comparison table for?
The term comparison table shows the monthly payment, total repaid, total interest, and interest as a percentage of the amount borrowed for all seven common terms (one to seven years) simultaneously. This eliminates the need to adjust the term slider back and forth to compare options. The selected term is highlighted, but all seven are visible at once.
The table is designed to answer the question: what is the shortest term where the monthly payment fits my budget? By scanning down the “monthly” column until the figure is affordable, then checking the “interest” column at that row, the borrower can see exactly what the affordable term costs in total. Clicking any row updates the main result panel to show that term’s figures in full.
Can I use this calculator for a secured loan?
The formula is the same (reducing-balance, monthly compounding), so the monthly payment and total cost figures will be accurate for any fixed-rate loan. However, secured loans have a different rate range (typically 4% to 16% APR), longer available terms (up to 25 or 30 years), and additional costs (arrangement fees, valuation fees, legal fees) that this calculator does not include. For secured loan calculations, the secured loan calculator is the more appropriate tool, as it accounts for the wider term range and includes fee modelling.
For unsecured personal loans between £1,000 and £25,000 over one to seven years, this calculator covers the standard range and produces the figures needed for the borrowing decision.
Squaring Up
This calculator shows the three numbers that matter in any personal loan decision: the monthly payment (can I afford this?), the total repaid (what does this cost?), and the total interest (what am I paying for the timing?). The term comparison table is the feature that makes the trade-off between monthly affordability and total cost visible without guesswork. Use it to find the shortest term where the monthly payment fits the budget, and the total cost column will show exactly what that choice costs. All figures are illustrative.
Explore all loan guides and tools
Everything in one place, across secured loans, debt consolidation, and home improvementsThis calculator is for illustrative purposes only and does not constitute financial advice. Monthly repayment figures use the standard annuity formula (reducing balance, monthly compounding). The APR you enter is illustrative. The rate offered to any individual depends on their credit profile, income, existing commitments, and the lender’s own criteria. The advertised representative APR is only guaranteed to at least 51% of accepted applicants. Missed repayments can affect your credit rating and may result in further action.
