Debt Payoff Calculator

What this calculator does

Debt has a way of feeling permanent. The balance moves slowly, the payments keep leaving, and there is rarely a clear answer to the only question that matters: when does this end.

This calculator answers it. Enter your outstanding balance, the annual interest rate and what you pay each month, and it works out exactly how many months remain, how much interest you will pay in total, and what you will have handed over by the time it is finished. Then it shows you what happens if you add a little more each month.

That last part is usually the surprise. On a high interest balance, an extra ten or fifteen thousand naira a month can remove a year from the term and save a six figure sum in interest, because every naira of extra payment attacks the principal directly and removes all the future interest that principal would have generated.

How the calculation works

The calculator simulates your debt month by month rather than using a closed formula, which lets it handle any payment amount you enter. Each month it adds the interest charged on the current balance, subtracts your payment, and carries the new balance forward. It counts months until the balance reaches zero.

There is one important threshold. If your monthly payment is less than the interest charged that month, the balance grows instead of shrinking and the debt never clears. The calculator checks for this and tells you the minimum payment required before any progress is possible. A lot of people paying a minimum amount on an expensive balance are in exactly this position without realising it.

The comparison table runs the same simulation at several higher payment levels so you can see the trade off directly, in months saved and naira saved, rather than in the abstract.

The formula

Interest charged this month = Outstanding balance × (Annual rate ÷ 12 ÷ 100)

New balance = Outstanding balance + Interest charged − Payment made

Minimum payment for any progress = Balance × Monthly interest rate

The process repeats until the balance reaches zero. Total interest is the sum of every monthly interest charge.

A worked example

Someone owes ₦850,000 at 30 per cent a year and pays ₦60,000 a month. The monthly interest rate is 2.5 per cent, so the first month adds ₦21,250 in interest and only ₦38,750 of the payment reduces the balance.

At that pace the debt clears in 17 months, and the total interest comes to roughly ₦168,000. The full amount repaid is about ₦1,018,000 against ₦850,000 borrowed.

Now add ₦15,000 a month, bringing the payment to ₦75,000. The debt clears in 13 months instead of 17, and the interest falls to about ₦126,000. Four months saved and ₦42,000 kept, for an extra ₦15,000 a month over just over a year. The reason the return is so strong is that the extra payment goes entirely to principal, and every naira of principal removed early cancels all the interest it would have accumulated for the rest of the term.

Things worth knowing

Clear the most expensive debt first

When you are carrying several debts, put every spare naira against the one with the highest interest rate while paying the minimum on the rest. This costs you the least in total. Some people prefer clearing the smallest balance first for the psychological win, and if that is what keeps you going, it is a legitimate choice.

Talk to the lender early

Lenders are generally far more willing to restructure a loan before a default than after one. If the payment is becoming unmanageable, a conversation in month two is a different conversation from one in month eight with charges accumulated.

Watch out for rollovers

Short term lenders often offer to roll an unpaid balance into a new loan with fresh fees. Each rollover adds cost to a balance you already could not clear. It solves this month and worsens every month after it.

Build a small buffer alongside

Putting every available naira into debt repayment feels disciplined until the first unexpected expense sends you straight back to borrowing. A modest emergency buffer kept separate is what stops the cycle restarting.

Common mistakes to avoid

Paying an amount that does not cover the monthly interest, so the balance grows while you make payments.
Focusing on the smallest balance when a much more expensive debt is quietly accumulating.
Rolling over a short term loan repeatedly and adding fresh fees each time.
Putting every spare naira into repayment with no buffer, then borrowing again at the first emergency.
Comparing a weekly or monthly quoted rate against an annual one without converting.
Missing a payment without contacting the lender, which usually triggers charges that could have been avoided.

Frequently asked questions

Should I pay off debt or save first?

Build a small emergency buffer first so that an unexpected cost does not send you back into borrowing. After that, clearing high interest debt usually beats saving, because few savings products return anything close to what expensive credit costs.

Which debt should I clear first?

Mathematically, the one with the highest interest rate, because it is costing you the most for every month it survives. Psychologically, some people do better clearing the smallest balance first to build momentum. Both approaches work if you stick to them.

Why is my balance barely moving?

Because most of your payment is going to interest. Run your figures through this calculator and look at the first month of the schedule. If the interest portion is close to your whole payment, the balance will move very slowly until you increase the payment.

Does paying early always save money?

On a reducing balance debt, yes. On a flat rate loan where the interest was fixed at the outset, possibly not, and some agreements charge an early settlement fee. Check the agreement before making a large lump payment.

Is this financial advice?

No. This tool performs arithmetic on figures you provide. We are not financial advisers and cannot assess your circumstances. For personal guidance, speak to a licensed financial adviser or a recognised debt counselling service.