IPMT Function in Excel

What this does

IPMT returns how much of a given payment is interest rather than principal. Because interest is charged on the outstanding balance, the figure is highest at the start and declines as the balance falls — which is why paying extra early saves disproportionately more than paying extra late. Summing IPMT across every period gives the total interest cost of the loan, the number that makes a long term expensive in a way the monthly payment hides. CUMIPMT does that summation in one call. Most people learn this as a sequence of clicks and forget it by next week; learning it as a pattern instead is what lets you apply it to the next, slightly different version of the problem without starting from scratch. That is the difference this page is trying to make. For “ipmt function in excel”, the reliable version is a short checking loop, not just the first command that appears to work. Run it on a deliberately small range first, watch how the affected formula change, and only then apply the same setup to the full sheet. When a formula is involved, keep the inputs labelled beside it, reference cells instead of typing values, and apply number formatting only after the result checks out. That is what makes a calculation you can defend to a CFO or an auditor useful in real work: repeatable, auditable, and not dependent on memory or luck.

A worked example

On a 200,000 loan at 5 % over 25 years, =IPMT(5%/12, 1, 300, 200000) returns about -833 of interest in month one, falling to roughly -5 by month 300. Total interest over the life is =CUMIPMT(5%/12, 300, 200000, 1, 300, 0), around -150,700 — three quarters of the amount borrowed again. IPMT exposes the true cost of borrowing over time, which the level monthly payment is very good at concealing. If there is any chance you will reuse this, drop it into a small template tab right now: a labelled input area on the left and the formula beside it, checked once against the tool above. Next time the same question comes up, the answer is a single paste away instead of a rebuild from memory.

In Google Sheets

Google Sheets handles this almost identically to Excel. The formula syntax above is the same, and the menu lives under a slightly different label rather than a ribbon tab. Use the platform toggle at the top of the page to switch every keyboard shortcut between Windows and Mac, and expect at most cosmetic differences in naming. Keep this page bookmarked for the next time the same question comes up. Better still, rebuild the example once in your own sheet — doing it yourself, with the tool above to check against, is what turns a copied formula into a technique you own. The short version of “ipmt function in excel”: the answer is at the top of this page, the tool proves it on your own numbers, and the sections above explain why it holds so the next variation does not stump you. Excel rewards people who reference cells instead of typing values and who keep inputs separate from formulas, because that is what makes a result you can audit months later. Build it once, deliberately, with the live tool as a check, and you convert a one-off lookup into a reusable skill — which is the whole point of learning the why and not just the what.

Common mistakes

• Mixing an annual rate with a monthly period count, which inflates every figure.
• Summing IPMT over a partial range and calling it the total interest; make sure the range covers every period.
• Reading the negative sign as a mistake rather than the outgoing-cash convention.

Frequently asked questions