Percentage Calculator
Solve percentage-of, reverse percentage, percent change, increase and decrease questions with the formula made explicit. Processing takes place locally in yo…
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What Percentage Calculator does
Solve percentage-of, reverse percentage, percent change, increase and decrease questions with the formula made explicit.
Worked example
A jacket costs 0 and is discounted by 20%.
Discount: ; sale price: 0
How the result is produced
A percentage is a ratio per hundred. Percentage of a value uses p ÷ 100 × n. Percent change uses (new − original) ÷ original × 100. Reverse percentage solves the same equation for the missing value.
Useful workflows
- Discount, sales-tax and tip checks
- Growth or decline between two reporting periods
- Commission, grade and survey-share calculations
Important limits
- Percent change is undefined when the original value is zero.
- A 20% increase followed by a 20% decrease does not return to the starting value.
- Percentage points and percent change are different measures.
Frequently asked questions
What is the difference between percent and percentage points?
Moving from 40% to 50% is an increase of 10 percentage points, or a 25% relative increase.
How do I reverse a discount?
Divide the discounted amount by one minus the discount rate written as a decimal.
What is the difference between percentage points and percent change?
A rise from 20% to 25% is 5 percentage points but a 25% relative increase.
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