Student Loan Overpayment Calculator United Kingdom

UK student loans do not work like a normal debt. There is no fixed monthly bill tied to the balance: you repay a percentage of income above a threshold, interest is added to the balance in the background, and whatever is left after a set number of years is written off. This calculator applies the 2026/27 thresholds and rates to your salary so you can see your repayment and judge whether paying extra is worth it.

How UK student loan repayments are calculated

Take your salary, subtract your plan’s threshold and pay a percentage of the rest: 9% on Plans 1, 2, 4 and 5, and 6% on a Postgraduate loan. The balance does not affect what you pay. A graduate with a £20,000 balance and one with £60,000 on the same salary and plan repay the same amount, because the repayment is limited by income, not debt. That drives every overpayment decision.

The 2026/27 thresholds

For 2026/27 the thresholds are £26,900 for Plan 1, £29,385 for Plan 2, £33,795 for Plan 4 (Scotland), £25,000 for Plan 5 and £21,000 for Postgraduate loans. Only income above the threshold counts; below it you repay nothing that year, whatever your balance. The government reviews these figures each year, so the calculator stores them as parameters and updates them for each new tax year.

Should you overpay?

Overpaying only makes sense if you would otherwise clear the balance before write-off. Repayments stop when the debt is cleared or the write-off date arrives, whichever comes first, and many borrowers with modest salaries and large balances never repay in full; for them the loan works more like a graduate tax, and a voluntary overpayment pays off a debt that would have been cancelled. A high earner who would clear the balance a decade before write-off is paying real interest meanwhile, and overpaying can save money. Compare the years to clear with the years left until your loan is written off.

A worked example

Suppose you are on Plan 2, earning £35,000, with £45,000 outstanding. Your income above the £29,385 threshold is £5,615, and 9% of that is £505.35 a year, about £42.11 a month. Ignoring interest, a £45,000 balance would take about 89 years to clear at that rate. Plan 2 loans are written off after 30 years, so you would never come close, and overpaying would almost certainly be wasted. At £60,000 the repayment rises to £2,755.35 a year and the years to clear fall to about 16, which changes the picture.

Why interest changes the picture

The years to clear figure ignores interest. In reality interest is added every year, and on some plans it is substantial: Plan 2 interest is linked to RPI and can be several points above it for higher earners. For a borrower whose repayment barely covers the interest, the balance can grow even while they pay, and ordinary repayments will never clear it before write-off. If the calculator shows a years to clear figure far longer than the years left until write-off, interest is almost certainly outrunning your repayments, and any extra you pay goes into a balance that would have been cancelled. Only when you are clearly on track to repay in full, well inside the write-off window, does overpaying reduce the interest you will really pay.

Common mistakes to avoid

• Overpaying out of a dislike of debt without checking whether you would ever clear the loan. For many borrowers the loan is written off first, so overpayments bring no benefit.
• Choosing the wrong plan. Your threshold and write-off period depend on your plan, so check your online repayment account if you are unsure.
• Treating the loan like a credit-file debt. UK student loans do not appear on your credit report, so clearing one early for your credit score is misguided.
• Assuming this year’s threshold and rate are fixed. The government reviews them each year, which changes your repayment and payoff timeline.
• Overpaying while carrying expensive debt such as a credit card, which almost always costs far more than the student loan.

Assumptions and limitations

This is a planning estimate, not a statement of your account. The years to clear figure divides your balance by your current yearly repayment and ignores interest, salary growth, threshold changes and the timing of deductions, all of which move the real payoff date. It uses the 2026/27 thresholds and the 9% undergraduate and 6% postgraduate rates, stored as parameters sourced from gov.uk and reviewed each tax year. It does not decide your plan or model more than one loan at once. For your exact balance and write-off date, check your account with the Student Loans Company before making any overpayment.

About This Student Loan Overpayment Calculator

Use this student loan overpayment calculator to get an instant, accurate estimate. The figures follow official GOV.UK guidance and every rate and threshold is kept up to date for 2026. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.