How to pay off a loan early
By David Chen · Published September 26, 2026
An extra payment does two things at once: it reduces the balance, and it removes every future interest charge that balance would have generated. The second effect is the large one, and it shrinks the later you leave it — which is why the most useful question about paying ahead is not how much, but when.
The numbers below are all from one mortgage, $300,000 at 6.50% over 30 years, with a monthly payment of $1,896.20. The same arithmetic applies to any fixed-rate instalment loan; only the scale changes.
The same $10,000, five different moments
One payment of $10,000, made at five points across the life of the loan, with everything else left as scheduled:
| When the $10,000 is paid | Amount | Interest saved | Term shortened by |
|---|---|---|---|
| Payment 1 | $10,000 | $53,917 | 33 months |
| Payment 61 — year 5 | $10,000 | $37,356 | 24 months |
| Payment 121 — year 10 | $10,000 | $24,871 | 18 months |
| Payment 241 — year 20 | $10,000 | $8,668 | 9 months |
| Payment 301 — year 25 | $10,000 | $3,598 | 7 months |
$300,000 at 6.50% over 30 years, extra payment applied to principal at the start of the stated month. Produced by our calculator and independently recomputed.
Read the first and last rows together. The same $10,000 removes $53,917 of interest at the start and $3,598 at year 25 — a difference of almost fifteen times, from the same money and the same loan. Nothing about the borrower changed; only the date.
Why the gap is that large
Interest is charged on the balance, month by month. When you pay down the balance in month 1, that amount stops generating interest for the remaining 360 months. When you pay it down in month 301, it stops generating interest for the remaining 60. The saving is proportional to the months of interest you prevented, and there are simply fewer of them late in the loan.
There is a second effect working in the same direction. In the early years, most of each payment is interest rather than principal — on this loan principal does not overtake interest until month 233. An extra payment in that period is doing work that the scheduled payment is barely doing at all.
Scaled down to a single $1,000, the same shape appears and is easier to hold in mind:
| A single $1,000 paid at | Interest saved |
|---|---|
| Payment 1 | $5,940.48 |
| Payment 121 — year 10 | $2,646.96 |
| Payment 301 — year 25 | $382.82 |
Same $300,000 loan at 6.50% over 30 years, one extra $1,000 applied to principal. Produced by our calculator and independently recomputed.
A lump sum or a steady habit?
Both work, and they are not equivalent per dollar:
| Approach | Money you put in | Interest saved | Saved per dollar in |
|---|---|---|---|
| $10,000 in payment 1 | $10,000 | $53,917 | $5.39 |
| $100 a month until it clears | $31,200 | $60,995 | $1.95 |
The monthly approach runs until the loan clears, which takes 312 payments of $100. Both measured against the same $382,633 baseline.
The lump sum is roughly 2.8 times more efficient per dollar — $5.39 of interest saved for each $1, against $1.95. The reason is timing: a dollar paid in month 1 works for 360 months, while a dollar paid in month 300 works for 60. Spreading the same money across years means most of it arrives too late to do much.
That is the arithmetic, and it is worth being honest about what it leaves out. A monthly extra payment is within most budgets and can be stopped in a bad month; a lump sum is irreversible and may consume the reserve that protects you. Efficiency is not the only thing being optimised.
A car loan: less to save, but faster feedback
Shorter loans have less interest to remove overall, but the balance falls quickly and the payoff date moves visibly — which is why they are often the better place to start:
| Extra each month | Paid off in | Months saved | Interest saved |
|---|---|---|---|
| As scheduled | 60 months | — | — |
| $50 a month | 54 months | 6 months | $607 |
| $100 a month | 49 months | 11 months | $1,089 |
| $200 a month | 41 months | 19 months | $1,808 |
$25,000 at 8.00% over 60 months, monthly payment $506.91, total interest $5,415 as scheduled. Produced by our calculator and independently recomputed.
An extra $100 a month — about 20% of the payment — clears the car loan eleven months early and saves $1,089. The absolute saving is modest because the loan is small, but the ratio of saving to effort is high, and the freed-up $506.91 a month is money that can be redirected at whatever comes next.
When paying early is the wrong move
- You hold a more expensive debt. Paying a 6.50% mortgage while carrying a 22% card balance is a guaranteed loss. Clear the higher rate first; the arithmetic is not close.
- You have no reserve. Money sent to the lender is very hard to get back, and the loan will still be there next month. A reserve that covers several months of payments has a value that does not appear in any interest calculation.
- There is a prepayment penalty. Some loans charge for paying down or paying off early, most often in the first few years. Check the documents — the penalty can exceed the interest saved.
- The rate is below inflation or below your alternatives. A fixed rate that is low in real terms is cheap money to hold. Paying it down is still a certain return equal to the rate, but it may be less attractive than the uses that cash has elsewhere — the comparison has to be made explicitly rather than assumed.
- You have not funded retirement accounts with tax advantages. Whether that matters depends on your situation and on the rules where you live; it is a question for someone who can see your whole position, not a rule of thumb.
Three mechanics worth checking first
Before sending anything extra, confirm three things in your loan documents or with the servicer, because each one changes where the money goes:
- How the extra is applied. On most fixed-rate instalment loans, an extra payment goes to principal and shortens the term. But some servicers treat it as an early instalment instead, which does nothing until the following month and saves nothing in between. Ask which one applies.
- Whether it shortens the term or reduces the payment. Term reduction keeps the payment where it is and saves the most interest. A recast lowers the payment and stretches the schedule back out, which is a different decision and usually the wrong one if the goal is to be debt-free sooner.
- Whether one large payment is allowed. Some loans restrict how much can be paid ahead in a given period. That is the same clause that carries the penalty, so it is read in one pass.
To see the effect on your own numbers before committing, the amortization schedule shows the balance month by month and how extra payments move the end date, and the biweekly guide covers the other common way of paying ahead — one extra payment a year, split across the calendar. If the loan has mortgage insurance, extra payments remove that too; see how to remove PMI.
The short version
Paying early works by removing future interest, so the same money is worth several times more at the start of a loan than near the end — $10,000 saves $53,917 in month 1 and $3,598 in month 25. A lump sum is more efficient per dollar than a monthly habit, but less flexible and harder to reverse. Do the arithmetic on your own loan, check how extra payments are applied and whether there is a penalty, and clear any higher-rate debt and fund a reserve before sending money to a cheap loan.
Frequently asked questions
Does paying off a loan early hurt my credit?
It reduces your outstanding debt, which helps the amounts-owed portion of most scoring models, and it closes an account, which can slightly shorten your credit history and reduce the mix of credit types. For most people the debt reduction outweighs the rest. It is a scoring question rather than a lending question — a loan you have cleared is not a reason to refuse you a mortgage.
Is it better to pay a lump sum or pay extra every month?
For interest saved, a lump sum early is more efficient per dollar: $10,000 in payment 1 removes $53,917 of interest on a $300,000 loan, while paying $100 a month until it clears removes $60,995 in total but requires $31,200 of your money. The reason is that early dollars have more months left to save interest on. Steady payments win on flexibility, not on efficiency — you can stop them, and a lump sum is gone.
Should I pay off my mortgage early or invest?
There is no universal answer, but the comparison has to be made honestly on both sides. Paying a 6.50% mortgage has a certain, tax-free return of 6.50% in avoided interest. An investment has an uncertain return, and its advantage is only real if the after-tax return exceeds the mortgage rate. The relevant question is not which has the higher average return but whether you can tolerate the outcome where the investment underperforms and the mortgage is still there.
Can extra payments be refused or penalised?
Some loans carry a prepayment penalty for paying off or paying down ahead of schedule, especially in the first few years; many mortgages have none. The terms are in your loan documents and should be checked before sending money, because the penalty can exceed the interest saved. There are also rules about when a lender must credit an extra payment, so it is worth confirming how yours is applied.
Should I pay off the smallest loan first or the highest rate?
Highest rate first is the better arithmetic — every dollar goes where it earns the most. Smallest balance first is sometimes the better plan, because clearing an account entirely removes a fixed monthly obligation and that is often what keeps people going. Since the difference in outcome is usually modest and the difference in adherence is often large, the method you will actually continue with is the better one.
Related guides
- How loan amortization works — The formula term by term, a worked month-by-month example, when principal finally overtakes interest, and why extra early payments save so much.
- Biweekly payments: what they really save — How paying half your mortgage every two weeks works, the exact saving on a worked loan, and the fees and pitfalls to avoid first.
- How to compare loan offers — Why the headline rate is not the comparison, the three numbers that are, and how to work out whether discount points are worth paying.
- APR vs interest rate — What each number actually measures, what APR leaves out, and the cases where comparing APR will lead you to the wrong lender.
Run your own numbers in the loan calculator.
Calculators for this topic
- Amortization schedule — The full month-by-month and year-by-year breakdown of a fixed-rate loan, and how much interest an extra payment removes from the end of it.
- Student loan calculator — Payment and total interest on a student loan, plus what a modest extra monthly payment does to the payoff date — the cheapest interest saving there is.
- Mortgage calculator — Monthly payment with property tax, home insurance, HOA and PMI folded in — the number that actually leaves your account, not just principal and interest.
This guide is educational and is not financial advice. Figures were produced by our calculator and independently recomputed before publication; your lender's own documents govern your loan. Spot an error? Tell us — see also our disclaimer.