Calculator · Plan 1
Plan 1 Student Loan Calculator: Will You Repay Before Write-Off?
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 1 student loan calculator projects your repayments year by year to the 25-year write-off, using Bank of England bond market inflation data rather than a fixed guess. Plan 1 covers England and Wales students who started before September 2012, all Northern Irish undergraduates, and Scottish students who started before August 2007.
Plan 1 is the plan where the numbers most often favour paying attention. Interest is capped, the write-off arrives sooner than any other plan, and balances are typically smaller, so many Plan 1 borrowers genuinely will repay in full. That changes the overpayment question completely.
Repayment threshold
£26,900
Interest rate
Lower of RPI or Bank Rate + 1%
Written off after
25 years
Who is on it
England/Wales pre-2012; NI all years; Scotland pre-2007
2025-26 tax year values. Thresholds change each April; verify at gov.uk.
How is a Plan 1 repayment calculated?
Annual repayment = 9% × (salary − £26,900)
At £35,000 salary:
9% × £8,100 = £729/year (£60.75/month)
Interest on an £18,000 balance at RPI 3.2% = £576/year
Balance falls by £153 in year one and faster each year after
Because Plan 1 interest can never exceed Bank Rate + 1% (currently a 5.25% cap, with RPI below it), repayments overtake interest at a much lower salary than on Plan 2. Most Plan 1 borrowers still repaying today are in the final stretch of their term.
Should I overpay a Plan 1 student loan?
Plan 1 is the one plan where overpaying is often rational. If the calculator shows you clearing the balance comfortably before the 25-year write-off, every pound of voluntary repayment saves the capped interest on that pound for the remaining term. The savings are modest but real, and they are close to risk-free.
The exception is a borrower close enough to write-off that the remaining schedule of repayments no longer clears the balance. In that case the standard logic applies: money sent to a balance that will be cancelled anyway is money lost. Run the projection first, then read our overpayment guide before sending anything.
Why use this Plan 1 student loan calculator?
Most calculators apply one interest assumption to every plan. Plan 1’s cap means its rate follows whichever of RPI or Bank Rate + 1% is lower, so a realistic projection has to model both paths. This calculator prices forward RPI from the gilt market for every year of your remaining term and applies the cap year by year. The full methodology explains how.
Run your Plan 1 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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