Estimate monthly repayments, total interest, and the payoff acceleration effect of optional extra payments on a personal loan.
Last updated
Debt Management
Enter your loan details and an optional extra monthly payment to see how much interest you save and how many months earlier you pay off the loan compared to the standard amortisation schedule.
Extra payments go directly toward reducing the principal balance. Since interest is calculated on the remaining principal, reducing it faster means less total interest accrues and the loan is paid off earlier.
Even small extra payments compound over time. An extra 100/month on a 25,000 loan at 6.5% over 5 years can save hundreds in interest and shave months off the term.
The standard monthly payment uses the amortisation formula.
M = P × r(1+r)ⁿ / ((1+r)ⁿ − 1)
P = principal, r = monthly rate (annual rate / 12), n = total months. Extra payments are applied on top of M each month.
Assumes fixed interest rate and that extra payments are applied monthly without prepayment penalties. Some loans charge early repayment fees — check your loan agreement. Does not model variable rates or payment holidays.
Frequently asked questions
Most do, but some loans include prepayment penalties, especially fixed-rate mortgages and certain auto loans. Always check your loan agreement before making extra payments.
Compare your loan interest rate to your expected investment return after tax. If the loan rate is higher, extra payments provide a guaranteed ‘return’ equal to the interest rate saved. If investment returns are higher, investing may be more beneficial — but carries risk.
Both reduce total interest. A lump sum has more impact earlier in the loan when the principal is highest. Regular extra payments build the habit and compound steadily over time.
Yes. The same amortisation formula applies to any fixed-rate loan — personal loans, auto loans, and mortgages. For mortgages, also consider whether biweekly payments might be more practical than monthly extras.
Also in Saving & Investing
You may also need
Related
These related calculators come from the same leaf category, nearby sibling categories, or the same top-level topic.
Calculate monthly loan payments, payoff timing, total interest, and the effect of extra payments.
Estimate monthly mortgage payments, total interest, and yearly amortization with country-aware housing costs and extra payments.
Generate a full loan amortization schedule showing monthly principal, interest, and remaining balance.
Plan your path to debt-free using the snowball or avalanche method, with total interest, payoff date, and method comparison for multiple debts.
