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Percentage Decrease Calculator

Work out how much a value dropped in percent — price cuts, weight loss, traffic dips and budget reductions. Enter the old and new numbers; the calculator shows the decrease and its formula.

The decrease formula, once and for all

Percentage decrease measures a drop relative to where you started: (old − new) ÷ old × 100. A budget cut from $12,000 to $9,000 is (3,000 ÷ 12,000) × 100 = 25%. The percentage calculator above computes it in "Percent change" mode and prints the formula with your numbers, so you can audit the result instead of trusting it. Expect a minus sign: −25% change is the same fact as a 25% decrease, stated with direction.

Discounts, dips and shrinkage

This is the calculator of sale seasons and quarterly reviews. Was that "30% off" real? Original $129, sale $89 — that is a 31% decrease, close enough. Website traffic fell from 48,000 to 39,000 visits? An 18.75% decrease — the number a report needs, not just "traffic is down". Weight from 82 kg to 76 kg is a 7.3% decrease. Same formula, every domain. For the upward direction, the percentage increase calculator mirrors this page, and the percentage difference calculator handles pairs where neither value is "the start".

The recovery asymmetry

Decreases and increases do not cancel. Lose 50% and you need +100% just to break even, because the percentages apply to different bases. Keep this in mind with investments and pricing: deep decreases are disproportionately expensive to climb out of.

Private by design

Figures stay in your browser. Nothing you calculate here is uploaded, stored or shared.

Frequently asked questions

How do you calculate percentage decrease?

Subtract the new value from the old value, divide by the old value, and multiply by 100. From $80 to $60: (80 − 60) ÷ 80 × 100 = a 25% decrease.

Why does the calculator show a negative number?

The percent-change mode reports direction with a sign: negative means the value went down. A result of −25% is exactly a 25% decrease — read the size, and let the sign confirm the direction.

A price fell 20% then rose 20% — is it back to the start?

No. Down 20% from $100 is $80; up 20% from $80 is $96. Percentages attach to different bases, which is why a 50% loss needs a 100% gain to recover.

Can percentage decrease exceed 100%?

For quantities that cannot go below zero, no: a 100% decrease means the value reached zero. Negative values (debts, temperatures) break the intuition, and percent change stops being meaningful there.

Is my data uploaded?

No. The calculation runs entirely in your browser — prices, salaries and weights stay on your device.

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