Reverse-discount solver
Recover an item's original price from its sale price and discount.
Percently • Everyday percentage math
%Percentage Calculator
Find a percentage of a number, percentage change, or the original value in seconds.
Top toolThree ways it saves you time
Profit-margin calculator
Calculate margin directly from cost and selling price.
Everyday percentage modes
Handle portions, ratios and increases or decreases in one tool.
20% of 80
16Calculated result
Using this tool
Choose the relationship before calculating
Select the question you want to answer, then enter the two values. Percently handles common percentage questions such as part of a total, percentage change and finding an original number from a known percentage.
Reading the output
The reference value changes the answer
An 80 to 100 price change
If a price rises from 80 to 100, the increase is 20. Dividing 20 by the original 80 gives a 25% increase, not 20%.
Parts, wholes and relative change
Percentage = part divided by whole times 100. Percentage change = (new value minus old value) divided by old value times 100.
Use the original value for change
- For change, use the starting value as the denominator.
- A 50% decrease followed by a 50% increase does not return to the original value.
- Round money only at the final step when possible.
Before relying on the result
Negative and large percentages
Why can a percentage change be negative?
A negative result means the new value is lower than the original value.
Can the result be above 100%?
Yes. A part can be larger than its reference whole, and an increase can exceed 100%.