Percentage Decrease Calculator
Measure how far a value has fallen, or take a percentage off a starting number.
Percentage decrease
Measure a fall that happened, or apply one yourself.
You know both values and want the percentage.
You know the starting value and the percentage to remove.
Recent calculations
What percentage decrease means
A percentage decrease measures a fall against the value it fell from. It answers questions like how much a price dropped in a sale, how far output slipped this quarter, or how much weight a shipment lost in transit. As with increases, the original value is the yardstick — a drop of 200 is catastrophic for a value of 250 and barely noticeable for a value of 250,000.
How to use it
Use the first tab when both numbers are known and you want the percentage between them. Use the second when you want to knock a percentage off a figure, which is the same calculation a shop performs when it marks something down.
The formulas
Worked example
Weekly sales falling from 80 units to 60
- Find the fall: 80 − 60 = 20
- Divide by the original figure: 20 ÷ 80 = 0.25
- Multiply by 100: a 25% decrease
Taking 18% off a 250 subscription
- Convert: 18 ÷ 100 = 0.18
- Find the reduction: 0.18 × 250 = 45
- Subtract: 250 − 45 = 205, or simply 250 × 0.82
Common mistakes
Cancelling an increase with an equal decrease. A 20% rise followed by a 20% fall leaves you below where you began: 100 goes up to 120, then down to 96. The percentages are taken from different bases.
Stacking two discounts by adding them. A 30% discount followed by an extra 20% off is not 50% off. It is 0.7 × 0.8 = 0.56 of the original, which is a 44% discount overall.
Using the new value as the base. Going from 80 to 60 is a 25% decrease, not a 33.3% one. That 33.3% figure is the increase you would need to get back from 60 to 80, which is a different question.