Should spare money go into paying off your UK student loan early, or into investments like a stocks & shares ISA? Enter your details and this tool simulates both futures, month by month, until your loan is repaid or written off.
Loan interest follows the official formulas using your inflation figure: Plans 1, 4 and 5 charge RPI (Plans 1 and 4 are capped at 1% above the Bank of England base rate when that's lower). Plan 2 scales from RPI up to RPI + 3% as income rises between £29,385 and £52,885. Postgraduate loans charge RPI + 3%. Salary, thresholds and interest bands are uprated once a year. We assume investments sit in a stocks & shares ISA, so returns are tax-free. Income tax and National Insurance don't change this comparison — your spare cash and your loan repayments both come out of post-tax pay under either strategy, so they cancel out. Pension contributions matter only when paid by salary sacrifice, which lowers the pay used to work out repayments and Plan 2 interest.
Projected balance until it's repaid or written off
What your spare money grows into under each choice (freed-up repayments are invested too)