Two questions, one tool
Repaying a loan is a balance between how much you pay each month and how long it takes. This calculator lets you fix one side and solve for the other. In "time" mode you set a monthly payment and it counts the months needed to clear the balance. In "payment" mode you set a number of months and it computes the payment that finishes exactly on schedule.
Both modes apply the same logic underneath: each month interest accrues on the remaining balance, your payment is applied, and the balance falls until it reaches zero.
Reading your result
The headline figure changes with the mode — either the months to repay or the required monthly payment. Alongside it, the total interest shows the full cost of borrowing over that schedule.
The chart contrasts the original balance with the interest you pay on top of it. A higher payment (or shorter term) shrinks the interest slice; a lower payment stretches the loan and grows it.
Practical pointers
When planning your repayment, keep these in mind:
- In time mode, the payment must exceed the first month’s interest or the balance will never fall — the tool will flag this.
- Small increases to a monthly payment can cut both the payoff time and total interest more than you would expect.
- Use payment mode when you have a deadline (such as clearing a debt before a life event) and need to know the amount required.
Scope
This models a single fixed-rate balance with level monthly payments and no fees. It is a planning aid; confirm exact figures, fees and any rate changes with your lender.
Formula
time mode: simulate balance += interest − payment until zero; payment mode: payment = P·r / (1 − (1+r)⁻ⁿ)Frequently asked questions
- Which fields matter for each mode?
- Time mode uses the monthly payment to find the number of months. Payment mode uses the term in months to find the payment. The other field is ignored.