Percentage Decrease Calculator

Percentage decrease = (old − new) ÷ old × 100. To apply: new = old × (1 − decrease% ÷ 100).

How to calculate a percentage decrease

A percentage decrease measures how much a value has fallen relative to where it started. Take the difference between the old and new figures, divide by the old figure, and multiply by 100. As with an increase, the decrease is always measured against the original value, not the reduced one. So a fall from 250 to 200 is 50 ÷ 250 = 20%, not 50 ÷ 200 = 25%. If instead you know the percentage and want the reduced value, multiply the original by one minus the rate as a decimal: 250 cut by 20% is 250 × 0.80 = 200.

This calculator does both. In find mode, enter the old and new values to get the percentage decrease, the absolute drop, and the multiplier. In apply mode, enter a value and a percentage to get the reduced figure. The multiplier — a 20% decrease is the same as multiplying by 0.8 — is the quickest way to chain reductions or, by dividing instead, to recover the original.

Worked examples: A price dropping from $250 to $200 → (250 − 200) ÷ 250 × 100 = 20% decrease. Applying a 20% reduction to $250 → 250 × 0.80 = $200. An asset depreciating from $30,000 to $24,000 is a 20% decrease (×0.8).

Sale prices, depreciation and declines

The same calculation covers most everyday reductions. For a sale, the percentage decrease is the discount from the customer’s point of view, and applying it gives the sale price. For an asset losing value — a car, equipment, a stock — the annual percentage decrease is how depreciation or a decline is usually expressed. For any falling metric — sales, traffic, headcount, weight — the percentage drop states the size of the decline on a comparable basis, regardless of the starting number.

This is the pure percentage tool: it works on any numbers, not just money, and it does not add tax or framing. If you specifically want a shopping discount with the price and savings spelled out, the discount calculator is purpose-built for that; this one stays general so it fits salaries, measurements, statistics and anything else that goes down.

Why a decrease and the matching increase don’t cancel

A value cut by 20% and then raised 20% does not return to where it started — it ends up 4% lower, because the increase applies to the already-reduced amount (0.8 × 1.2 = 0.96). This asymmetry catches people out constantly: to undo a 20% decrease you must increase by 25%, not 20%, since 1 ÷ 0.8 = 1.25. The multiplier makes it clear — divide by 0.8 to reverse the cut, and the answer is a 25% increase.

Sequential decreases compound the same way. Two successive 10% markdowns are not 20% off but 19% off, because the second applies to a smaller base (0.9 × 0.9 = 0.81). Use the sequential-decreases option under advanced to chain several reductions and read off the single equivalent percentage — the honest figure behind stacked “extra % off” sale tags.