Student Loan Interest Calculator

Calculate your student loan interest rate by income. See how fast your balance grows with compound interest.

Last updated: April 2026 · Source: GOV.UK — Repaying your student loan

£
£

Your Interest Rate

5.36%

£2,411.38/year · £200.95/month · £6.61/day

Current Balance

£45,000.00

Balance in 5 Years (no repayments)

£58,420.18

Plan 2 interest:

Below £27,295: RPI (4.3%)

£27,295–£49,130: RPI + up to 3%

Above £49,130: RPI + 3% (7.3%)

Disclaimer

This calculator is provided for informational purposes only and should not be considered as financial or tax advice. All calculations are performed locally in your browser — no personal data is collected or sent to our servers. Rates and thresholds are sourced from HMRC and GOV.UK and are updated for the current tax year. Always verify results with HMRC or consult a qualified professional before making financial decisions.

How It Works

Interest on student loans accrues from the day the loan is paid out, including while you are still studying. For Plan 2 loans, the rate is linked to RPI (Retail Prices Index) plus a margin of up to 3% depending on income. While studying, you are charged RPI + 3%. After graduation, the rate scales from RPI (income ≤ £27,295) to RPI + 3% (income ≥ £49,130).

For Plan 5 loans (started from 2023/24), interest is capped at RPI only, with no additional income-based margin. This means Plan 5 borrowers pay lower interest than Plan 2 borrowers at the same income level.

This calculator shows the interest accruing on your balance each month and year, based on your current balance, plan type and income. It also shows how much of your monthly repayment goes to interest versus reducing the principal. For many graduates, repayments do not cover the interest, and the balance grows until it is written off.

Example: Plan 2, £45,000 balance, £35,000 salary, RPI 3.5%

  1. Interest rate: RPI + partial margin ≈ 4.2%
  2. Annual interest: £45,000 × 4.2% = £1,890
  3. Monthly repayment: (£35,000 − £27,295) × 9% ÷ 12 = £57.79
  4. Annual repayment: £693.45 — balance grows by ~£1,197/year

Source: GOV.UK — Repaying your student loan

Frequently Asked Questions

What does the Student Loan Interest Calculator do?
Calculate your student loan interest rate by income. See how fast your balance grows with compound interest. All calculations are performed in your browser using official UK rates and thresholds.
Does this use current UK interest rates?
You can enter any interest rate to model different scenarios. The Bank of England base rate and FCA guidelines influence typical lending rates available in the UK market.
Should I get professional debt advice?
If you are struggling with debt, free professional advice is available from StepChange (0800 138 1111), Citizens Advice, and the National Debtline (0808 808 4000). This calculator provides estimates only.