Debt-Free Date Calculator

A debt-free date calculator that turns a pile of balances into a single answer: the month you’ll finally be debt-free, how much interest you’ll pay to get there, and exactly which debt clears when. It’s built for anyone juggling a credit card, a car loan, a store card and an overdraft at once who wants a realistic, motivating plan rather than a vague “pay more when you can”.

Add each debt with its balance, annual interest rate and minimum payment, then tell the tool the total amount you can put toward debt every month. It models the whole journey month by month and reports your payoff date, the total interest, a balance-over-time chart and the payoff order — and saves everything privately in your browser so you can come back and adjust as life changes.

How it works

The calculator runs a proper month-by-month simulation rather than a rough formula. For each month it: charges interest on every outstanding balance at the APR divided by twelve, applies the required minimum payment to each debt, and then directs every spare pound of your budget at one focus debt. Which debt gets the focus depends on your chosen strategy.

• Avalanche attacks the debt with the highest APR first. Because interest is the real cost of borrowing, this order always produces the lowest total interest and the earliest mathematically possible payoff date.
• Snowball attacks the smallest balance first. You clear whole debts quickly, which many people find far easier to stick with — the behavioural win often beats the small extra interest cost.

All arithmetic is done in whole pence to avoid floating-point rounding drift, and the simulation guards against impossible inputs: if your budget can’t cover the combined minimums or even the monthly interest, it tells you so instead of producing a fantasy date. A baseline run with minimums only is computed alongside so the tool can show how much interest and time your extra payments actually save.

Example

Suppose you owe £4,200 on a credit card at 22.9%, £8,500 on a car loan at 7.4% and £1,300 on a store card at 29.9%, with minimum payments of £105, £190 and £40. Paying just the minimums, this drags on for years and costs thousands in interest.

Set a £600/month budget on the avalanche strategy and the calculator clears the store card first, then the credit card, then the car loan — showing a debt-free date roughly two and a half years out, the total interest you’ll pay, and the months and interest you saved versus minimums-only. Switch to snowball and watch the payoff order and date shift so you can decide which plan you’ll actually keep to.

Every figure is calculated in your browser — no numbers are uploaded or stored.