How Much Can I Borrow Calculator
This calculator works out how much you can borrow when you already know the monthly payment you can afford. You choose a monthly payment, an annual interest rate (APR) and a term in months, and it shows the loan amount that fits those figures. It is the usual loan payment formula worked backwards, so the answer is the amount a repayment plan could support.
For example, a monthly payment of £500.00 at 7% APR over 60 months gives an amount you can borrow of £25,251.00. Over the full term you would pay £30,000.00 in total, which means £4,749.00 of that is interest. Use the figures as a guide to your budget, and check the final numbers with the lender or bank before you rely on them.
How to use the how much can i borrow calculator
- Enter the monthly payment you are comfortable paying, in pounds.
- Enter the interest rate (APR) as a percentage.
- Enter the term of the loan in months.
- Read the amount you can borrow from the result.
- Check the total paid and total interest to see the full cost over the term.
- Change one input at a time to see how a higher payment, rate or term affects the amount.
The formula
- Amount = payment × (1 − (1 + r) ^ −n) ÷ r, where r is the annual rate ÷ 12 ÷ 100 and n the number of months
- Total paid = payment × n; total interest = total paid − amount
Worked example
The figures below are made up to show the maths. They are not current prices, rates or product figures.
| Monthly payment | £500.00 |
|---|---|
| Interest rate (APR) | 7% |
| Term | 60 months |
- Amount you can borrow £25,251.00
- Total paid £30,000.00
- Total interest £4,749.00
Tips for an accurate answer
- Use the APR quoted by the lender, as it includes charges that a simple rate may not.
- Leave some room in your monthly payment for bills and unexpected costs rather than stretching to the maximum.
- Confirm the final figures with the lender or bank, as this calculator shows the maths only and is not financial advice.
Questions people ask
How much are you allowed to borrow?
This calculator does not set a limit on what you are allowed to borrow. It shows the amount that a monthly payment, rate and term would support mathematically. Lenders decide what they will actually offer based on their own checks.
Can this calculator show how much I can borrow from a specific lender?
No, this calculator does not use any lender's criteria or rates. It only works out the amount from the payment, rate and term you enter. To find out what a particular lender will offer, contact them directly.
How much can I borrow for a mortgage with this calculator?
The calculator shows the loan amount that a chosen monthly payment, interest rate and term would support. Enter the mortgage rate and term you are considering to see the figure. Lenders will confirm the actual mortgage amount after their own assessment.
What does this calculator actually work out?
It works out the loan amount that a monthly payment would cover at the rate and term you enter. It reverses the usual repayment calculation to find the borrowing figure. It is a guide to the maths, not a lending decision.
Why does a longer term change the amount I can borrow?
With a longer term, each monthly payment is spread over more months, so the same payment supports a larger loan. The trade-off is that you pay more interest overall, which the total interest result shows.
Is the interest rate I enter the same as the APR?
This calculator uses the rate you enter as the annual rate, so it is best to enter the APR quoted by the lender. The APR is designed to include certain charges, so it gives a more complete picture of the cost.
Can I rely on this as my final borrowing limit?
No. The calculator only shows the mathematical result for the figures you enter. A lender will assess your income, outgoings and credit history separately, so check the actual amount with them.
What should I enter as my monthly payment?
Enter the amount you could comfortably pay each month after your essential costs are covered. Entering a figure you can only just manage may leave little margin for changes in your circumstances.
Sources
This calculator uses the standard loan and interest formulas above and the numbers you type. It needs no outside figures.
An estimate from the numbers you enter, worked out with the formula shown. It is maths, not financial advice: your lender or bank has the final figures. Page checked 23 Oct 2026. Read the disclaimer