About this calculator
The Student Loan Repayment Calculator estimates UK student loan repayments based on plan type, income, repayment threshold, repayment percentage, interest assumptions, and write-off period. It is useful for graduates, employees, self-employed borrowers, postgraduate loan holders, and students comparing what salary changes may mean for monthly deductions. The calculator is designed for Plan 1, Plan 2, Plan 4, Plan 5, and postgraduate loan-style scenarios.
Student loan repayment method
UK student loan repayments are normally based on income above the plan threshold, not the outstanding balance. GOV.UK explains that repayments are a percentage of income over the threshold. For many undergraduate plans the rate is 9% above the threshold, while postgraduate loans use a different percentage. Interest and write-off rules then affect whether the balance is ever cleared.
- repayable income = max(0, annual income - plan threshold)
- annual repayment = repayable income x repayment rate
- monthly repayment = annual repayment / 12
- new balance = opening balance + interest - repayments
- write-off result depends on plan type and years remaining
How to use the student loan calculator
- Choose the student loan plan that applies to you.
- Enter your annual salary or expected income.
- Enter outstanding loan balance if the calculator asks.
- Add postgraduate loan details separately if relevant.
- Review monthly and annual repayment estimates.
- Run salary scenarios to see how deductions change with pay rises.
- Use the result for planning, not as a replacement for payroll or Student Loans Company records.
Worked examples
Repayment above threshold
Input: Income GBP 35,000 and plan threshold GBP 25,000
Calculation: GBP 35,000 - GBP 25,000 = GBP 10,000 repayable income
Result: At a 9% repayment rate, annual repayment is GBP 900, or GBP 75 per month.
Below threshold
Input: Income below the plan threshold
Calculation: Repayable income is treated as zero
Result: No repayment is due through salary for that period.
Postgraduate loan alongside undergraduate loan
Input: Borrower has undergraduate and postgraduate loan deductions
Calculation: Each loan type can have its own threshold and repayment percentage.
Result: Payroll deductions can include both if income is above both thresholds.
Plan type matters
Student loan deductions depend on the plan, and plan thresholds can change by tax year. The same salary can create different deductions for Plan 1, Plan 2, Plan 4, Plan 5, and postgraduate loans. Use the correct plan from your Student Loans Company account, payslip, or HMRC records.
Inputs to check
| Input | Why it matters | Where to check |
|---|---|---|
| Plan type | Sets threshold and rules | SLC account or payroll notice |
| Income | Repayments are based on income above threshold | Payslip, P60, or self-employment profit |
| Repayment threshold | Changes the taxable-like excess used | GOV.UK current thresholds |
| Interest rate | Affects balance growth | SLC statement |
| Write-off period | Affects whether full repayment is likely | Plan rules |
Payroll and self-assessment
Employees usually repay through payroll when income is above the threshold. Self-employed borrowers may repay through Self Assessment. A calculator estimate can differ from payslip deductions if income is uneven, bonuses are paid, plan details are wrong, or a stop notice has not reached payroll.
Common student loan mistakes
- Using the wrong plan type.
- Assuming repayments are based on the whole salary instead of income above threshold.
- Ignoring postgraduate loan deductions alongside undergraduate loan deductions.
- Assuming interest charged means you will definitely repay the full balance.
- Comparing annual estimates with a bonus-heavy payslip without allowing for payroll timing.
Student finance information disclaimer
This calculator is for general education finance planning only and is not tax, payroll, or financial advice. Student loan thresholds, interest rates, write-off rules, and plan rules can change. Check GOV.UK and Student Loans Company records for current details.
- It does not access your SLC account.
- It may simplify interest and write-off behaviour.
- Payroll deductions can differ because of pay timing, bonuses, or employer records.
Frequently asked questions
How are UK student loan repayments calculated?
Repayments are usually a percentage of income above the threshold for your plan, not a percentage of the full loan balance.
Which student loan plan do I have?
Check your Student Loans Company account, repayment notices, payslip, or GOV.UK plan guidance.
Do I repay if I earn below the threshold?
Usually no repayment is due through salary if income is below the plan threshold for that pay period.
Can I have undergraduate and postgraduate deductions?
Yes. If your income is above the relevant thresholds, both deductions can apply.
Will I repay the loan in full?
That depends on income growth, interest, balance, plan type, and write-off rules. Many borrowers make repayments without clearing the full balance.
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