Calculator · Plan 5
Plan 5 Student Loan Calculator: The 40-Year Projection
Written by Zubair Arshed FIA, Chartered Actuary
Fellow of the Institute and Faculty of Actuaries
Actuarial Post Life and Health Actuary of the Year 2024
This Plan 5 student loan calculator projects your repayments across the full 40-year term for England and Wales courses starting from August 2023, using the gilt market’s inflation curve for every one of those years.
A 40-year horizon is precisely where fixed-assumption calculators break down. Assuming 3% inflation for four decades is not a forecast, it is a shrug. Plan 5 borrowers deserve better, because the plan’s design means many will be repaying into their sixties.
Repayment threshold
£25,000
Interest rate
RPI only, no surcharge
Written off after
40 years
Who is on it
England/Wales, from August 2023
2025-26 tax year values. Thresholds change each April; verify at gov.uk.
How is a Plan 5 repayment calculated?
Annual repayment = 9% × (salary − £25,000)
At £30,000 salary:
9% × £5,000 = £450/year (£37.50/month)
The same salary on Plan 2 would repay just £55/year
Interest is RPI only, so the balance grows with inflation and no more
Plan 5 asks for more, earlier, from lower earners, in exchange for never charging an interest surcharge. Whether that trade helps or hurts you depends almost entirely on your salary path over four decades.
Will I still be repaying my Plan 5 loan at 60?
Possibly. A graduate who starts repaying at 22 reaches write-off at 62, and the lower threshold means repayments start early and stop rarely. The design intent was that far more borrowers repay in full than under Plan 2, which also means fewer escape via write-off. The calculator shows your projected payoff or write-off year explicitly, so you can see which side of that line you fall on.
With a term this long, small differences in salary growth compound enormously, which is why this calculator models your industry’s wage curve rather than a flat percentage. For the full picture of how the plan works, read our Plan 5 guide.
Why use this Plan 5 student loan calculator?
Because Plan 5 interest is pure RPI, your projection is only as good as its inflation forecast, for 40 consecutive years. This calculator reads a distinct market-implied RPI figure for each future year from the gilt breakeven curve, the same data professional investors trade on. The methodology page shows exactly how the curve becomes your projection.
Run your Plan 5 projection
The calculator infers your plan from where and when you studied, then projects every year to payoff or write-off. Free, no account needed.
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