With inflation, an instalment six months from now is worth less than the same instalment today. That's why "interest-free instalments" doesn't mean "same as cash": it depends on how much you expect prices to rise in the meantime. This calculator does that maths with your numbers: it has no inflation figure built in, you enter it.
The calculator
Enter the monthly inflation you expect to see the result. At 0% the present value equals the instalment total.
Educational tool. The result depends on the inflation you enter and is not financial advice nor a recommendation to buy or invest.
How it's calculated
The calculator brings every instalment back to the present. If the monthly inflation you expect is i, the instalment you pay k months from now is worth instalment ÷ (1 + i)^k today. The first instalment (k = 0) is worth its face value; the second is divided by (1 + i); the third by (1 + i)²; and so on. The sum of all of them is the present value of the instalments, which is compared with the cash price.
Worked example. Suppose a product costs $300,000 in cash or 6 interest-free instalments of $50,000, and you expect 2% monthly inflation. The instalments are worth $50,000 + $49,020 + $48,058 + $47,116 + $46,192 + $45,287 = $285,673 today. Under those assumptions, the instalments are worth $14,327 less than cash today. With 0% expected inflation, both options would be worth exactly the same.
If the instalments carry interest (the instalment total is higher than the cash price), the maths is the same: the present value can end up above or below the cash price depending on the inflation you assume. The calculator shows both differences, nominal and present value, because the first is what you see on the receipt and the second is what matters.
The calculator assumes the first instalment is paid at purchase. In practice, with a credit card, the first one lands with the statement closing date, one or two months later, so the result is conservative: the instalments are worth even a little less today than it says.
Where to get the inflation figure
The calculator deliberately has no figure built in: any value written here would be read as "the official one" and go stale the following month. In Argentina the latest published figure is INDEC's monthly CPI, released mid-month with the previous month's value. You can use that, an average of recent months, or whatever you expect for the months the plan lasts: it's your assumption, and the result holds for that assumption.
- If you think inflation will fall during the plan, try a lower number than the latest published one and see how much the result changes.
- If the plan is long (12 or 18 instalments), the assumption matters more: a 1-point monthly difference changes the present value of instalment 18 a lot.
- Inflation isn't the only thing that matters: so is whether you'll be able to pay each instalment without falling back on the card's minimum payment, which does carry interest.
Take the instalments to Kesef
If you bought in instalments, in Kesef you log the purchase once with the total and the number of instalments, and each month gets its own. That way you see how much of next month is already committed before it arrives, with a reminder the day before each due date. It's free.
Frequently asked questions
Are interest-free instalments free?
Nominally you pay the same as in cash. But with inflation, the instalments you pay later are worth less in real terms than the same money today: that's why, with positive inflation, the present value of interest-free instalments ends up below the cash price. By how much depends on the inflation you assume and the number of instalments.
What if the instalment price is higher than the cash price?
The calculator accepts an instalment total that differs from the cash price. In that case the instalments carry an implicit interest, and the present value can end up above or below the cash price depending on the inflation you expect. Compare the present-value difference, not the nominal one.
Which inflation figure should I enter?
The one you expect for the months the plan lasts. In Argentina the latest published figure is INDEC's monthly CPI; you can use that or an average. The calculator has none built in because any number written here goes stale and reads as official.
Does it account for a cash discount?
Yes: enter the discounted price as the cash price. That's exactly the comparison worth making: discounted cash against the instalment total.
Does the calculator make a recommendation?
No. It says what the instalments are worth today with the inflation you entered and which of the two options is worth less under those assumptions. It's arithmetic, not advice: the decision also depends on whether you'll be able to pay each instalment without interest, and on your situation.
Sources and review date
Checked on October 13, 2026. External figures change: if you're deciding based on this, it's worth confirming the number at the source.