Monthly payment and total cost for student loan repayment

Student loans are not like other debt

Most loan calculators assume you'll pay back every pound borrowed plus interest. Student loans don't work that way. They're income-contingent, time-limited, and written off entirely after 25-40 years depending on plan type. Many graduates — possibly most — will never repay the full amount. The relevant question isn't "how long until I pay this off?" but "how much will I actually pay, given my expected earnings and plan type?" This calculator estimates total repayment; the commentary below is what that figure actually means for your decisions.

The five plan types that determine everything

Student loan terms depend on when you started university:

Plan 1 (pre-2012 /; all): Repayment threshold 24,990. Interest: the central bank base rate + 1% or RPI (whichever is lower). Written off at 25 years or age 65 (whichever sooner).

Plan 2 (2012-2022 /): Threshold 27,295. Interest: RPI + up to 3% while studying; RPI to RPI+3% depending on income after. Written off at 30 years.

Plan 4: Threshold 31,395. Interest: Bank base rate + 1%. Written off at 30 years or age 65.

Plan 5 (2023+, undergraduate): Threshold 25,000. Interest: RPI only (during studies and after). Written off at 40 years.

Postgraduate (Masters/PhD): Threshold 21,000. Interest: RPI+3%. Written off at 30 years. Stacks on top of any undergraduate plan.

The differences aren't cosmetic. Plan 2 graduates on 40k earning career paths often pay more than Plan 1 graduates because of higher interest. Plan 5 graduates will pay longer (40 years) but at lower rates. The calculator above estimates based on your specific plan; the plan type drives the projection.

The 9% deduction reality

You repay 9% of income above your plan's threshold (6% for Postgraduate Loan, stacked separately). For a Plan 2 borrower earning 40,000: (40,000 - 27,295) × 9% = 1,143/year or about 95/month. This continues for 30 years or until the balance is cleared, whichever happens first. For most Plan 2 borrowers in standard careers, the 30-year write-off arrives before the loan is cleared.

The counter-intuitive "pay more, pay less" pattern

Because of how income-contingent repayment works, paying extra into a student loan can cost you money in long-run terms. If you'd be write-off-eligible anyway (most Plan 2 borrowers on typical graduate salaries), voluntary overpayments just mean you paid down a loan you wouldn't have repaid anyway. The 5,000 you overpay is 5,000 that could have gone to pension, tax-advantaged savings account, or mortgage — any of which would have compounded in your favour rather than cleared a balance that would have disappeared. This is the opposite of how standard debt works, and it's one of the most commonly-misunderstood aspects of student loans.

When paying extra does make sense

A few specific scenarios where voluntary overpayment is worth considering:

You're earning very high salaries consistently (over 85,000+ on Plan 2, over 60,000+ on Plan 5). At these levels, the full balance including interest is likely to be paid anyway, and saving interest helps.
You're already maximizing pension and tax-advantaged savings account contributions and have no other debt.
You'll receive a large windfall (inheritance, business sale) that can't be easily deployed elsewhere.
You strongly dislike the psychological weight of the loan and would trade financial optimization for peace of mind.

For most typical graduate careers, these conditions don't apply. The default answer for most Plan 2 and later borrowers is: don't overpay; treat it as a graduate tax that disappears after 30-40 years.

The interest rate variation

Plan 2 interest is complicated: RPI while studying and earning below threshold, scaling up to RPI+3% at 49,130+ income (figures). This means high earners pay dramatically more total interest than low earners on the same nominal balance. A 50k graduate balance on Plan 2 with 10% annual interest can compound to 100,000+ before repayments bite. For borrowers whose earnings will stay modest, interest barely matters because write-off happens first. For high-earning Plan 2 borrowers in law, consulting, banking, or senior roles, interest accumulation is a real concern.

The tax wedge implication

Student loan deduction acts as an effective additional tax. For a Plan 2 borrower in the standard tax rate band: 20% income tax + 8% NI + 9% student loan = 37% total marginal rate. For a upper-rate taxpayers: 40% + 2% + 9% = 51%. Factor in 9% more for Postgraduate Loan stack (total 60%). This matters for decisions like bonus vs pension contribution — putting bonus into pension avoids the student loan deduction entirely, making pension contributions disproportionately valuable for student loan borrowers.

The career path that works

The country student loan structure quietly rewards certain career decisions:

Careers with lumpy high earnings (finance, law partner track) pay the most.
Careers with moderate, steady earnings (public sector, academic) pay a moderate amount and often hit write-off.
Careers with low earnings (creative fields, charity sector, self-employment) often pay very little and reach write-off with most balance remaining.

This isn't a reason to choose career paths, but it does mean the "debt burden" of student loans varies wildly by life path. For lower-earning paths, the psychological weight often exceeds the actual financial weight.

What happens when you move abroad

Student Loan Company requires you to update them when moving abroad and make voluntary repayments based on a similar income-contingent formula (but applied to foreign income). Many graduates move abroad and simply don't contact SLC. The practical consequences are mild: interest continues to accrue, no immediate enforcement action. If you return to the country, the accrued balance is waiting. If you don't return, the balance eventually gets written off anyway (same 25-30-40 year rule). The practical advice: technically you might notify SLC; practically many don't; the long-run outcome doesn't differ dramatically either way for most graduates.

The "loan" label is misleading

Student loans behave more like a graduate tax than traditional debt. The repayment is proportional to income. The obligation ends after a fixed period. Missing payments doesn't damage credit or produce default consequences (as long as you're below threshold). Mortgage lenders treat it as a monthly obligation but not as debt for borrowing capacity. In almost every meaningful way, student loan is closer to an income tax than a conventional loan. Framing it mentally as "graduate tax" rather than "debt" changes which financial decisions are rational.

What this calculator shows

The tool estimates total lifetime repayment based on your plan type, starting salary, and salary growth assumption. It doesn't automatically model mid-career changes (going part-time, moving abroad, returning to study) or handle the interaction with multiple plan types. Use the figure as the central projection for your expected career path; rerun with pessimistic and optimistic salary assumptions to see the range.