Percentage Decrease Calculator

Put the higher starting number first. A fall is labeled decrease, not left as a bare minus sign.

Same formula, downward result

A decrease is not a separate kind of math. It is a percent change that came out negative. Take a jacket marked down from $80 to $60. The price fell by $20. Divide 20 by the original 80 and you get 0.25, so the markdown is 25%.

People sometimes divide by the new price instead. That mistake turns this sale into 20 / 60, or about 33%, which overstates the discount. The baseline for a decrease is the price before the cut, just as the baseline for an increase is the price before the hike.

Watch the baseline when you reverse it

After a 25% decrease, $80 is $60. Putting 25% back onto $60 only returns $75, not $80. The original is 60 / (1 − 0.25) = 80. Use Reverse mode when you know the later number and the percent, and you need the earlier one.

A starting value of 0 still cannot show a percentage decrease. There is nothing to fall from, so the result stays undefined.

Questions people ask

How do you calculate a percentage decrease?

Subtract the new, smaller value from the original, divide by the original, and multiply by 100. You can also run the increase formula and read a negative result as a decrease. From 80 to 60 is a 25% decrease.

Is a 50% decrease the reverse of a 50% increase?

No. A 50% increase takes 80 to 120. A 50% decrease takes 80 to 40. To undo a 25% decrease you need a 33.3333% increase, not another 25% move.

What is a 100% decrease?

The new value is 0. Anything past that is more than a total loss of the original amount, which shows up as a percent below −100% when the new value is negative.

Why does the page say decrease instead of only showing a minus?

The signed percent is still there, and the word decrease is printed with it. Color is not the only cue.

Percentage Decrease Calculator

Same formula, downward result

Watch the baseline when you reverse it

Questions people ask

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