UK student loan repayment calculator (Plans 1, 2, 4, 5 and Postgraduate)

The calculator runs one tax year at a time (6 April to 5 April), starting with 2026/27, and inside each year one month at a time.

The deduction. Each month: repayment = roundDown(rate × max(0, salary ÷ 12 − threshold ÷ 12), 0), with the rate at 9% for Plans 1, 2, 4 and 5 and 6% for a Postgraduate Loan. The result is rounded down to a whole pound, which is how HMRC’s PAYE tables work and why the GOV.UK example of £33,000 on Plan 2 gives £27 rather than £27.11. The weekly figure uses the same formula with 52 in place of 12.

Thresholds. Each plan has its own repayment threshold. The calculator uses the published 2026/27 figures (Plan 1 £26,900, Plan 2 £29,385, Plan 4 £33,795, Plan 5 £25,000, Postgraduate £21,000) and the published Plan 1 figure for 2027/28 (£28,005). After that, Plan 1 and Plan 4 rise with the RPI assumption each April; Plan 2 stays frozen until 2029/30 and Plan 5 and Postgraduate until April 2027, then rise with RPI as well. The salary grows at the growth rate you set.

Interest. Interest is added monthly at the annual rate ÷ 12 on the balance, rounded to the penny. For the academic year 1 September 2026 to 31 August 2027 the published rates are used; later years derive the rate from your RPI assumption using each plan’s rule (see below). The Plan 2 rate is set once a year from that year’s salary.

Write-off. At the start of the April that is the plan’s term after the April you were first due to repay (25 years for Plan 1, 30 for Plans 2 and 4 and Postgraduate, 40 for Plan 5), any balance left is cancelled and reported as the amount written off. The loop ends when every loan is cleared or written off.

Overpaying. When you enter a lump sum or a monthly overpayment, the projection runs twice, with and without it, and compares the total repaid. The verdict is simply whether the total with overpayments is lower. Lump sums come off the balance before month 1; monthly overpayments go to the first loan until it clears. Two loans are repaid under the GOV.UK stacking rules: a Postgraduate Loan plus an undergraduate plan takes 6% over £21,000 plus 9% over the undergraduate threshold; two undergraduate plans share a single 9% deduction over the lower threshold, apportioned between them.

Full method, rounding and tests on the methodology page

Which plan you are on depends on where you lived when you applied and when your course started. The repayment rule is the same shape on every plan: nothing below the threshold, a fixed percentage of everything above it, taken through PAYE alongside tax and National Insurance (or through Self Assessment if you are self-employed).

Because the deduction is a share of income above the threshold, a pay rise of £1,000 costs you £90 a year on an undergraduate plan, £60 on a Postgraduate Loan, and £150 if you have both. Combined with income tax and National Insurance, that is why graduates sometimes describe the loan as a 9% graduate tax. The size of the balance changes nothing about the monthly figure; it only changes how long the deductions last and whether they stop before the write-off.

The Plan 1 and Plan 4 thresholds rise every April in line with RPI. The Plan 2 threshold has been frozen at £29,385 until the 2029/30 tax year, and the Plan 5 and Postgraduate thresholds are frozen until April 2027. A frozen threshold with rising wages means a bigger deduction each year in real terms, which the projection reflects.

Interest rates are reset every 1 September from the previous March’s RPI figure, and the rule differs by plan:

• Plan 1 and Plan 4: the lower of RPI and the Bank of England base rate plus 1%. For 1 September 2026 to 31 August 2027 that is 4.1%. The calculator uses RPI for projected years; the base-rate cap is not modelled.
• Plan 2: a sliding scale. RPI (4.1%) if you earn £29,385 or less, rising on a straight line to RPI + 3% at £52,885 and above, capped this year at 6%: rate = min(cap, RPI + 3% × (salary − 29,385) ÷ (52,885 − 29,385)). GOV.UK’s own examples give 4.82% at £35,000 and 5.46% at £40,000. The scale means higher earners are charged more, which is the opposite of what happens on most loans.
• Plan 5: RPI only, 4.1% this year, with no earnings-related addition.
• Postgraduate Loan: RPI + 3%, capped at the prevailing market rate; for 2026/27 the cap applies and the rate is 6%.

Interest is applied to the balance every month, so the balance grows whenever the monthly interest is more than the deduction. In the worked example, £45,000 at 4.56% adds £2,088.58 of interest in the first year against £324 repaid, and the calculator shows a warning when that is the case. The loan payoff calculator shows the same interest-versus-payment arithmetic for an ordinary fixed-rate loan, where there is no write-off to rescue a payment that does not cover the interest.

Every plan cancels whatever is left after a fixed period counted from the April you were first due to repay, not from the day you borrowed: 25 years on Plan 1, 30 years on Plans 2 and 4 and on Postgraduate Loans, and 40 years on Plan 5. A Plan 1 loan first taken out before September 2006 is instead written off at age 65. Loans are also cancelled on death and, in some circumstances, if you become permanently unfit for work.

The write-off is what turns the arithmetic on its head. On a normal loan every extra payment saves interest. On a student loan that is heading for write-off, an extra payment only reduces the amount that is going to be cancelled, so it saves nothing at all. The calculator reports the write-off year and the amount cancelled, and its overpayment verdict compares total repaid with and without the extra money, which is the only comparison that matters.

Whether your loan reaches the write-off depends mainly on salary relative to the threshold. In the worked example the loan is cancelled after 30 years whether the borrower earns £33,000 or £55,000; it is only on a higher salary, or with a substantial overpayment on the higher salary, that the balance falls to zero first. Student loan deductions do not appear on your credit file and are not counted as a debt by the credit reference agencies, but lenders do take the deduction into account as a cost when they assess affordability; the debt-to-income ratio calculator shows how a fixed monthly commitment changes that ratio, and our guide to the debt-to-income ratio explains what lenders look at.

Plan 2 combines the three features that make overpaying least likely to help: a large balance (tuition fees of up to £9,250 a year plus maintenance), an interest rate that rises with salary up to RPI + 3%, and a 30-year write-off. For most Plan 2 graduates the deductions over 30 years never reach the balance plus interest, so the loan is written off and the total they repay is set by their earnings, not by what they owe. Paying extra reduces the balance, but the balance was never going to be repaid in full, so the extra money is simply gone.

The worked example makes the point with numbers. On £33,000, £100 a month extra for 27 years costs £32,400 and leaves the borrower still having the loan written off in 2053/54. A £10,000 lump sum now has the same effect: £10,000 more repaid, same write-off year. The verdict flips only when the loan would clear anyway, as it does on the £55,000 salary with £200 a month extra, which saves £24,414.41 by cutting 15 years of interest.

Three things decide which side of the line you are on: your salary relative to the threshold (the higher it is, the more you repay and the sooner you clear), how long you have until the write-off (a loan with five years left is cancelled whatever you do), and the interest rate relative to salary growth. Run your own figures with and without the overpayment, and try a higher salary growth rate to see how sensitive the verdict is. If you also have other debts, the debt payoff calculator and our guide to avalanche vs snowball show how to order them; a student loan that is heading for write-off behaves differently from the others in that queue, because extra payments do not reduce what it costs, whereas one that will clear is simply a loan at its interest rate.

Your employer calculates the deduction on each pay day from that period’s earnings, not from your annual salary. The threshold is divided into monthly (£2,448 for Plan 2) or weekly (£565) amounts, the rate is applied to the excess, and the result is rounded down to the whole pound. A bonus month therefore produces a much larger deduction that month and nothing is averaged out; the calculator’s monthly figure is the deduction you would see on a steady salary with no bonus.

With two jobs, each employer applies the full threshold separately, so someone earning £20,000 in each of two jobs on Plan 2 repays nothing through PAYE even though their total income is above the threshold. If you complete a Self Assessment tax return, HMRC calculates the repayment on your total income, including self-employed profits and unearned income over £2,000, and any shortfall is collected with your tax bill. The calculator models a single PAYE job; it does not model Self Assessment or multiple employments.

Two further details worth knowing. Deductions start from the April after you finish, but only once your pay is above the threshold, and they stop automatically when the Student Loans Company tells HMRC the balance is clear, although in the final year it is common to overpay slightly through PAYE and receive a refund. And if your income drops below the threshold, for example between jobs, deductions stop without any action on your part; interest continues to be added.

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• GOV.UK — Repaying your student loan: what you pay (thresholds and interest rates, 2026/27)
• GOV.UK — How interest is calculated: Plan 2 (sliding scale 1 September 2026 to 31 August 2027)
• GOV.UK — When your student loan gets written off or cancelled
• GOV.UK — Student loans: interest rates and repayment threshold announcement (Plan 1 threshold for 2027/28)

Estimates for general information only — not financial, credit or legal advice. Your actual figures depend on your lender’s or card issuer’s exact terms, fees, minimum-payment rules, interest calculation method and any changes they make. Check your statements and speak to a qualified adviser before making decisions. Thresholds, interest rates and write-off terms are the published 2026/27 figures; later years are projected from the salary growth and RPI assumptions you set, and the Student Loans Company’s figures and future policy changes can differ.

Page reviewed October 9, 2026 by the DebtWren team · Methodology · Changelog · Report an error