Student Loan Repayment Calculator
Stack your undergraduate and postgraduate loans to reveal the brutal combined impact on your take-home. Discover your true marginal tax rate — it might shock you.
Debt Settings
Configure your exact UK Student Finance portfolio
Stacks an additional 6% levy
Double Deduction Active
Both loans are currently pulling from your gross above their respective thresholds concurrently.
Annual Student Debt Paid
Net Take-Home: £26,400.15
Your Marginal Tax Rate
If you get a £100 payrise today, HMRC and the SLC will take £43.
Detailed BreakdownThreshold Mathematics
Undergraduate (plan2)
9% taken on earnings above £27,295
Postgraduate Loan
6% taken on earnings above £21,000
2026/27 Repayment Threshold Quick Guide
Student loan repayment is not triggered by simply having debt — it only activates once your post-tax income crosses a government-defined earnings floor. Here is exactly where each plan fires:
| Loan Type | Who It Covers | 2026/27 Threshold | Deduction Rate |
|---|---|---|---|
| Plan 1 | Pre-2012 English/Welsh | £24,990 | 9% |
| Plan 2 | Post-2012 English/Welsh | £27,295 | 9% |
| Plan 4 | Scottish graduates | £31,395 | 9% |
| Plan 5 | Post-2023 English graduates | £25,000 | 9% |
| Postgraduate | Masters / PhD (Post-2016) | £21,000 | 6% |
The 47% Marginal Tax Trap
The uncomfortable truth about payrises for postgraduate debtors.
If you earn between £27,295 and £50,270 and hold both a Plan 2 and Postgraduate loan, a raw marginal calculation reveals you are surrendering 47p from every extra £1.00 earned:
- Income Tax (basic rate)20p
- National Insurance (employee)8p
- Plan 2 Undergraduate @ 9%9p
- Postgraduate Loan @ 6%6p
- Total Gone47p
Repayment vs Write-Off Strategy
Should you overpay your student loan?
Plan 2 Dynamics
Because Plan 2 is written off after 30 years regardless of the remaining balance, many graduates with average UK salaries will statistically never fully repay the loan. Making voluntary overpayments is often financially irrational unless you are confident you will clear the entire balance before write-off.
Postgraduate Loan Nuance
Postgraduate loans tend to be smaller (capped at £11,836 for 2026/27 Masters). A high-earning graduate might realistically clear this faster, making targeted overpayment more financially sensible than for the larger undergraduate balance.
Related Calculators
Tools that work alongside your financial planning.