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UK Student Loan Interest Rates: Complete Guide

Understanding current interest rates for all UK student loan plans, how they're calculated, and whether they actually matter for your repayments.

Student loan interest rates appear prominently in financial news, sparking anxiety among borrowers who watch their loan balances grow monthly. The reality, however, is more nuanced than headlines suggest. For most UK graduates, the interest rate on their student loan has minimal practical impact on their finances. This isn't because the rates are low—some reach 7.3%—but because of how UK student loans fundamentally work.

Unlike conventional loans where you pay a fixed amount monthly based on the balance and interest rate, UK student loan repayments are calculated as a percentage of income above a threshold. Whether your loan balance is £30,000 or £60,000, whether the interest rate is 1.75% or 7.3%, your monthly payment remains identical if your income is the same. The interest rate only determines how quickly the balance grows and whether you'll fully repay before the loan is written off after 30 years.

Government figures suggest 75-80% of recent graduates will never fully repay their loans before write-off. For these borrowers, higher interest rates are psychologically uncomfortable but financially irrelevant. The extra interest accrued each month increases a balance that will eventually be cancelled. It's like watching a debt grow that you know you'll never have to fully repay.

Interest rates do matter for higher earners likely to repay in full, those considering voluntary overpayments, and anyone trying to understand why their balance behaves unexpectedly. This guide breaks down current rates for every plan type, explains exactly how they're calculated, and helps you determine whether your loan's interest rate actually affects your financial situation or is just noise to ignore.

Current Interest Rates (2023)

Interest rates vary significantly between loan plans, reflecting different policy approaches across England, Wales, Scotland, and Northern Ireland:

Plan 1

1.75%

Lower of Bank of England base rate + 1% or RPI

Applies to:

  • English/Welsh students who started before September 2012
  • Scottish and Northern Irish students

Plan 2

Variable: 4.3%-7.3%

RPI to RPI + 3% (income dependent)

  • • While studying: 7.3% (RPI + 3%)
  • • After graduation, earning below £27,295: 4.3% (RPI only)
  • • Earning £27,295-£49,130: 4.3%-7.3% (sliding scale)
  • • Earning above £49,130: 7.3% (RPI + 3%)

Plan 4

1.75%

Lower of Bank of England base rate + 1% or RPI

Applies to: Scottish students who started September 2007 onwards

Plan 5

4.3%

RPI only (both during and after study)

Applies to: English students who started September 2023 onwards

Postgraduate Loan

7.3%

RPI + 3% throughout the entire loan

Applies to: Master's and doctoral loans in England and Wales

Note: Rates as of September 2023. RPI figure used: 4.3%. Interest rates are reviewed annually and adjust based on inflation measures.

Source: Student Loans Company

Use our Plan 2 Calculator, Plan 5 Calculator, or Postgraduate Loan Calculator to see how interest affects your specific loan balance over time.

How Student Loan Interest Rates Are Calculated

UK student loan interest rates are primarily based on either the Retail Price Index (RPI) inflation measure, the Bank of England base rate, or a combination of both:

Plan 1 and Plan 4 Interest Formula

For Plan 1 and Plan 4 loans, the interest rate is set at the lower of:

  • The RPI inflation rate (measured in the previous March)
  • The Bank of England base rate plus 1%

Example calculation (March 2023):

  • RPI (March 2023): 4.3%
  • Bank of England base rate: 4.25%
  • Base rate + 1%: 5.25%
  • Interest rate applied: 4.3% (the lower of the two)

This protective mechanism ensures that if inflation is high but the Bank of England base rate remains low, your interest rate stays relatively low, protecting borrowers during high inflation periods.

Plan 2 Interest Formula

Plan 2 has the most complex interest structure, varying based on your study status and income:

While studying:

RPI + 3% = 7.3% (with current RPI of 4.3%)

After graduation:

  • Earning below £27,295: RPI only = 4.3%
  • Earning between £27,295 and £49,130: Interest increases on a sliding scale from RPI to RPI + 3%
  • Earning over £49,130: RPI + 3% = 7.3%

Sliding scale calculation:

For incomes between thresholds, the formula is:

Rate = RPI + [(Income - £27,295) ÷ (£49,130 - £27,295)] × 3%

Example: Earning £35,000

  • Above threshold: £35,000 - £27,295 = £7,705
  • Range: £49,130 - £27,295 = £21,835
  • Proportion: £7,705 ÷ £21,835 = 0.353
  • Additional rate: 0.353 × 3% = 1.06%
  • Total rate: 4.3% + 1.06% = 5.36%

This progressive structure means higher earners pay more interest, though the actual repayment amount still depends on income, not the loan balance or interest rate.

Plan 5 Interest Formula

Plan 5 simplifies the interest calculation compared to Plan 2:

  • Interest is set at RPI only, both during and after your studies
  • Unlike Plan 2, there's no additional percentage added based on income
  • Current rate: 4.3% (matching the RPI rate)

This makes Plan 5 interest rates more predictable and generally lower than Plan 2 for higher earners. A graduate earning £50,000 would pay 7.3% interest on Plan 2 but only 4.3% on Plan 5—a 3% difference.

Postgraduate Loan Interest Formula

Postgraduate loans have the simplest formula, but potentially the highest rate:

  • Interest is set at RPI + 3% throughout the entire life of the loan
  • This rate applies regardless of income or study status
  • Current rate: 7.3%

Unlike undergraduate Plan 2, postgraduate loans don't have income-based interest adjustments. Whether you earn £22,000 or £100,000, the interest rate remains constant at RPI + 3%.

When are interest rates set?

Interest rates are reviewed annually and typically announced in late summer for the following academic/tax year. The RPI figure used is from the previous March. For example, the September 2023 rates use the March 2023 RPI of 4.3%.

Does Interest Rate Actually Matter?

A unique feature of UK student loans is that the interest rate often has less impact on your finances than you might expect:

Repayments Are Based on Income, Not Balance

Unlike conventional loans, your monthly repayments are calculated as a percentage of your income above the repayment threshold—not based on the size of your loan or the interest rate.

Example (Plan 2):

Scenario A:

  • Loan balance: £30,000
  • Interest rate: 4.3%
  • Annual salary: £32,000
  • Annual repayment: £423.45

Scenario B:

  • Loan balance: £60,000
  • Interest rate: 7.3%
  • Annual salary: £32,000
  • Annual repayment: £423.45

Despite doubling the loan balance and increasing the interest rate by 3%, the monthly payment is identical because repayments are calculated as: (£32,000 - £27,295) × 9% = £423.45.

Most Loans Are Never Fully Repaid

Government figures suggest that around 75-80% of recent graduates with Plan 2 loans will never fully repay their loans before they're written off after 30 years. Similar projections exist for Plan 5 loans.

What this means:

  • The interest rate has little practical impact on your finances if your loan will be written off
  • A larger balance due to higher interest doesn't matter if the loan will be cancelled anyway
  • You're effectively paying a 9% "graduate tax" on earnings above the threshold, not repaying a traditional loan

Example: Average earner

Graduate starts with £45,000 debt at 7.3% interest. Earns £30,000-£45,000 over career (average £37,500). After 30 years of repayments totaling approximately £28,000, the remaining balance of £85,000+ (grown due to interest) is written off. The 7.3% interest rate increased the written-off amount but didn't increase the total amount paid.

When Interest Rates Do Matter

Interest becomes more important in these scenarios:

Higher earners likely to repay in full:

If you're earning £60,000+ and likely to clear your loan within 20 years, the interest rate significantly affects your total repayment. At 7.3% vs 4.3%, you might pay £5,000-£10,000 more in total.

Voluntary repayments:

If you're considering making extra payments, the interest rate affects whether this makes financial sense. With a 7.3% rate, overpaying might be worthwhile. With a 1.75% rate, investing that money elsewhere likely yields better returns.

Psychological impact:

Watching your loan balance grow each month can be psychologically distressing, even if it doesn't affect your monthly repayments or total amount you'll pay. Understanding that most of this growth will be written off can provide peace of mind.

Common misconception:

"My loan balance is growing each month, so I'm falling behind and need to pay more."

This is false for most graduates. If you're earning below or near the threshold, your monthly repayments won't cover the interest, causing the balance to grow. This is completely normal and expected for 75-80% of borrowers. The system is designed this way. You're not "falling behind"—you're paying exactly what you should based on your income, and the excess will be written off.

Use our Investment vs Overpayment Calculator to see whether making voluntary repayments makes financial sense given your interest rate and expected earnings.

Historical Interest Rates

Interest rates on student loans have fluctuated significantly over time, primarily due to changes in inflation (RPI) and the Bank of England base rate:

Plan 1 and Plan 4 Historical Rates

Being linked to the lower of RPI or Bank Rate + 1%, these plans have seen relatively stable and low interest rates:

  • 2016-2020: Generally between 1.1% and 1.75%
  • 2020-2022: Dropped to just 0.1% due to historically low Bank of England rates during COVID-19
  • 2022-2023: Increased to current rate of 1.75% as Bank Rate rose to combat inflation

The protective "lower of" mechanism meant Plan 1 and 4 borrowers were shielded from the high inflation rates of 2022-2023, paying just 1.75% while RPI exceeded 11%.

Plan 2 Historical Rates

Being primarily linked to RPI, Plan 2 has seen more volatility:

  • 2012-2016: Generally between 3.3% and 5.5% for studying/higher earners
  • 2017-2022: Increased to a peak of RPI + 3% = 6.3% for higher earners
  • 2022-2023: Reached a maximum of 7.3% (RPI + 3%) for higher earners as inflation surged
  • 2023: Rate capped at 7.3% despite RPI exceeding 11% (due to government intervention)

2022-2023 crisis:

When inflation spiked to 11%+, the RPI + 3% formula would have resulted in interest rates exceeding 14%. The government intervened to cap rates at 7.3%, preventing extreme charges but still leaving Plan 2 borrowers with significantly higher rates than other plans.

Postgraduate Loan Historical Rates

Following the same RPI + 3% formula as Plan 2 while studying:

  • 2016-2021: Generally between 4% and 5.6%
  • 2022-2023: Peaked at 7.3%

Postgraduate borrowers face the same high rates as Plan 2 higher earners but without the income-based adjustments. Even earning £22,000, you pay 7.3% interest.

Future outlook:

Interest rates will continue to fluctuate with inflation and Bank of England policy. As inflation moderates from 2022-2023 peaks, rates are expected to gradually decrease, though they'll remain tied to economic conditions rather than being fixed.

Interest Rate Comparisons Between Plans

Comparing interest rates across plans reveals significant policy differences:

Loan PlanCurrent RateIncome-Based?Inflation Protection?
Plan 11.75%NoYes (capped at BoE + 1%)
Plan 24.3%-7.3%Yes (sliding scale)Partial (capped at RPI + 3%)
Plan 41.75%NoYes (capped at BoE + 1%)
Plan 54.3%NoNo (tracks RPI)
Postgraduate7.3%NoPartial (capped at RPI + 3%)

Best interest rates (currently):

  1. Plan 1 / Plan 4: 1.75% (most favorable)
  2. Plan 2 (low earners): 4.3%
  3. Plan 5: 4.3%
  4. Plan 2 (high earners): 7.3%
  5. Postgraduate: 7.3% (least favorable)

Most predictable rates:

  1. Plan 5: Simple RPI formula
  2. Postgraduate: Simple RPI + 3%
  3. Plan 1 / Plan 4: Lower-of mechanism adds complexity
  4. Plan 2: Sliding scale based on income (most complex)

Use our Plan 2 vs Plan 5 Comparison to see how interest rate differences affect your total repayment over time.

How Your Income Affects Interest Rates

Only Plan 2 loans have income-dependent interest rates. Understanding this mechanism helps Plan 2 borrowers anticipate rate changes as their career progresses:

Plan 2 Income Bands and Interest Rates

Annual IncomeInterest Rate FormulaCurrent Rate
Below £27,295RPI only4.3%
£27,295RPI + 0%4.3%
£30,000RPI + 0.37%4.67%
£35,000RPI + 1.06%5.36%
£40,000RPI + 1.75%6.05%
£45,000RPI + 2.43%6.73%
£49,130+RPI + 3%7.3%

Career progression example:

Age 22 (graduate): £25,000 salary → 4.3% interest

Age 25: £32,000 salary → 4.95% interest

Age 30: £42,000 salary → 6.32% interest

Age 35: £55,000 salary → 7.3% interest (maximum)

As your career progresses and salary increases, your interest rate automatically increases, even without any change in policy or inflation.

Common scenarios:

Promotion/raise: Interest rate increases immediately when new salary reported to HMRC

Job loss/reduction: Interest rate decreases to RPI only if income falls below threshold

Self-employment: Interest based on previous year's Self Assessment income

Maternity/paternity: Interest rate typically decreases due to reduced income

Should You Make Voluntary Overpayments?

Interest rates are the primary factor in determining whether voluntary overpayments make financial sense:

When overpayments likely make sense:

  • High interest rate (6%+): Paying down a 7.3% loan is equivalent to a guaranteed 7.3% return on investment
  • High income: Earning £50,000+ and likely to fully repay within 20 years
  • Rapid career growth: Salary increasing quickly, loan will be repaid soon anyway
  • Large windfall: Received inheritance, bonus, or other one-time payment

When overpayments likely DON'T make sense:

  • Low interest rate (below 4%): You can likely earn more by investing elsewhere
  • Average income: Loan will likely be written off, so overpayments just increase the amount written off
  • Uncertain career: Might have periods of low income or unemployment
  • Other debts: Credit cards, personal loans, or mortgage at higher rates should be prioritized

Break-even analysis example:

Scenario: Plan 2 loan, £40,000 balance, earning £45,000 (6.73% interest rate), considering £5,000 overpayment

Option A: Make £5,000 overpayment

  • Saves ~£3,200 in interest over loan life
  • Clears loan ~2 years earlier
  • Effective return: 6.73% guaranteed

Option B: Invest £5,000

  • Assuming 7% average annual return
  • After 15 years: ~£13,795
  • Better outcome IF you actually fully repay the loan

Verdict: If confident you'll fully repay, investing is slightly better. If uncertain, overpayment provides guaranteed return.

Use our Investment vs Overpayment Calculator to model your specific situation and make an informed decision.

Taking Control of Your Student Loan Interest

Understanding your interest rate isn't about obsessing over every percentage point. It's about making informed decisions and avoiding unnecessary anxiety:

Annual interest rate check:

  • Check current rate for your plan each September when rates are announced
  • Calculate annual interest you'll accrue: (Balance × Rate)
  • Compare to annual repayments: (Income - Threshold) × 9%
  • Determine if balance will grow, shrink, or stay stable

Decision points requiring interest rate consideration:

  • Career change: Will reduced income affect interest rate (Plan 2 only)?
  • Windfall: Should you use it for overpayment or investment?
  • Job offer negotiation: How will salary increase affect interest rate and total repayment?
  • Emigration: Different rules apply; might want to clear loan before leaving

Mental health approach to interest rates:

If watching your balance grow causes anxiety:

  • Remember: 75-80% of borrowers never fully repay. Balance growth is normal and expected.
  • Focus on your monthly repayment (9% of income above threshold), not the balance
  • Calculate your likely write-off amount to see the psychological "debt" that doesn't matter
  • Consider not checking your balance more than once per year
  • Reframe as a "graduate tax" rather than traditional debt

Resources and tools:

  • Check Student Loans Company website for official rate announcements
  • Use student loan calculators to model different scenarios
  • Consider speaking with a financial advisor if contemplating large overpayments
  • Monitor government policy changes that might affect rates or thresholds

Your student loan interest rate is one factor among many in your financial life. Understanding it empowers you to make informed decisions, but for most graduates, obsessing over it is counterproductive. Focus on your career growth, earning potential, and overall financial health. The loan system is designed to be income-contingent, making the interest rate less important than it would be for conventional debt.

Understand your interest rate. Model your scenarios. Make informed decisions. But don't let interest rate anxiety control your finances when, for most graduates, it has minimal practical impact on total lifetime repayments.

Use our student loan calculators for interest calculations, repayment projections, overpayment analysis, and write-off estimations.

👩‍🎓

Dr. Lila Sharma

UK Education Policy Specialist

With over 15 years of experience in UK education policy and student finance, Dr. Sharma founded Student Loan Calculator UK to help students navigate the complex world of student loans.