Start with our walkthrough explaining why balances grow, what the tipping point means and why outcomes differ so much between borrowers.
Every student loan outcome is shaped by two competing forces. Understanding how they interact is the starting point for every answer Wayli gives.
Interest is charged on the outstanding balance and may continue accumulating even while repayments are being made.
Repayments depend on earnings above the repayment threshold, not directly on the size of the balance itself.
Wayli models the relationship between these two forces over time to understand whether a balance is likely to grow, stabilise or shrink, before explaining what that could mean for your overall outcome.
Most student loan calculators stop after estimating repayments. Wayli goes further by interpreting what those numbers could mean over time.
Whether repayments are currently outpacing interest.
Whether the balance direction is changing over time.
How close you may be to the tipping point.
How salary changes could affect future repayments.
Whether full repayment currently looks likely.
How overpayments may alter long-term outcomes.
Write-off timelines for your repayment plan.
How repayment paths differ across earnings levels.
Two borrowers with similar balances can experience completely different long-term outcomes depending on salary growth, their repayment plan and whether repayments eventually begin overtaking interest.
UK student loan repayments are based on the portion of your income above your repayment threshold, rather than your full salary.
Most undergraduate plans currently use a repayment rate of 9%, while postgraduate loans use 6%.
Repayments only apply to earnings above the threshold - not your entire salary. This is why two people with similar balances can repay very different amounts each month.
This simplified example shows how interest and salary-based repayments interact over time.
In this example, interest is currently larger than repayments - so the balance continues growing despite repayments being made.
Adjust salary, balance and interest assumptions to see how changes can alter the direction of a student loan over time.
Interest is currently larger than repayments, so the balance continues growing over time.
Increasing salary often changes repayments much faster than changing the balance itself.
This is one reason two borrowers with similar balances can experience very different long-term repayment outcomes.
Wayli groups repayment trajectories into broad directional states to help explain what your balance may be doing over time.
Interest is currently outpacing repayments, so the balance may continue increasing.
Repayments and interest are becoming more closely matched over time.
Repayments are now reducing the balance more consistently.
Student loan outcomes can change dramatically depending on future income. Rather than assuming your salary stays the same forever, Wayli tests several possible futures.
0% annual salary growth
3% annual salary growth
5% annual salary growth
For each scenario, Wayli reruns the full loan projection to understand whether the balance is likely to grow, shrink or be fully repaid before write-off.
If every scenario points to the same outcome, your result is likely to be more robust. If small changes in salary produce very different outcomes, Wayli treats the result as more sensitive or closer to a tipping point.
A tipping point is reached when yearly repayments become greater than the yearly interest being added to the loan.
£40k salary
£50k balance
~£955 yearly repayments
~£3,100 yearly interest
Interest is higher than repayments, so the balance usually continues growing.
£63k salary
£50k balance
~£3,025 yearly repayments
~£3,100 yearly interest
Repayments are almost matching interest, so relatively small salary changes could alter the outcome.
£75k salary
£50k balance
~£4,105 yearly repayments
~£3,100 yearly interest
Repayments are now exceeding interest, so the balance usually begins falling over time.
This is why future salary growth can have such a significant effect on student loan outcomes. Relatively small changes in earnings may completely change how the loan behaves over time.
Wayli's repayment assumptions are updated regularly using current UK student finance guidance, repayment thresholds, repayment rates and write-off rules.
Repayment thresholds, interest rates and write-off rules can change over time. Wayli reviews these assumptions regularly, but future government policy may alter how student loans operate.
Wayli’s repayment assumptions are aligned with publicly available UK student finance guidance and updated annually in line with official repayment thresholds and repayment rules.
This includes guidance from Student Loans Company, Student Finance England, Student Finance Wales, SAAS Scotland and Student Finance Northern Ireland.
Use the Wayli Student Loan Calculator to calculate your own outcome.
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