Percentage Calculator
Calculate percentages in 4 modes: percent of, what percent, percent change, and increase/decrease.
How to Calculate Percentages
A percentage (%) represents a fraction of 100.
Mode 1 β X% of Y: Y Γ X Γ· 100
Example: 15% of 50,000 = 50,000 Γ 15 Γ· 100 = 7,500
Mode 2 β X is what % of Y: X Γ· Y Γ 100
Example: 30 is what % of 200? = 30 Γ· 200 Γ 100 = 15%
Mode 3 β Percent Change: (Y - X) Γ· X Γ 100
Example: 100 to 120 = (120 - 100) Γ· 100 Γ 100 = +20%
Mode 4 β Increase/Decrease: X Γ (1 Β± YΓ·100)
Example: $50,000 after 10% discount = 50,000 Γ 0.9 = 45,000
Common percentage pitfalls
- % vs. percentage points: a rate rising from 3% to 4% is a 1 percentage-point rise, but a 33% relative increase. Contracts and headlines often blur the two.
- A drop then a rise doesn't cancel out: 100 down 50% is 50; up 50% again is only 75. Recovering a 50% loss requires a 100% gain.
- Stacked discounts multiply: 20% off then 10% off is 28% off, not 30% (0.8 Γ 0.9 = 0.72).
Mode 1 β X% of Y: Y Γ X Γ· 100
Example: 15% of 50,000 = 50,000 Γ 15 Γ· 100 = 7,500
Mode 2 β X is what % of Y: X Γ· Y Γ 100
Example: 30 is what % of 200? = 30 Γ· 200 Γ 100 = 15%
Mode 3 β Percent Change: (Y - X) Γ· X Γ 100
Example: 100 to 120 = (120 - 100) Γ· 100 Γ 100 = +20%
Mode 4 β Increase/Decrease: X Γ (1 Β± YΓ·100)
Example: $50,000 after 10% discount = 50,000 Γ 0.9 = 45,000
Common percentage pitfalls
- % vs. percentage points: a rate rising from 3% to 4% is a 1 percentage-point rise, but a 33% relative increase. Contracts and headlines often blur the two.
- A drop then a rise doesn't cancel out: 100 down 50% is 50; up 50% again is only 75. Recovering a 50% loss requires a 100% gain.
- Stacked discounts multiply: 20% off then 10% off is 28% off, not 30% (0.8 Γ 0.9 = 0.72).
Frequently Asked Questions
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Content last reviewed: 2026-08-22