Percent calculator, use it like this
You can enter a total value and a ratio to find a partial value, or calculate the rate of change between two values. Use it for shopping discounts or data comparison.
Example usage
20% of 50,000 is 10,000. The 20% discount from 50,000 is 40,000.
Please note
The increase/decrease rate is (new value − old value) ÷ old value × 100. If the existing value is 0, the increase/decrease rate cannot be defined.
Step-by-step instructions
- Choose a calculation method among the percentage of the total value, the amount after discount, or the increase/decrease rate of the two values.
- Check the display of each item and enter the total value/ratio or existing value/new value.
- Check the results. The currency unit of the amount is the same as the value entered.
Calculation standards for ratios and increase/decrease rates
p% of the total value A is A×p÷100. The price discounted by p% is A×(1−p÷100). The increase/decrease rate from the old value A to the new value B is (B−A)÷A×100, and if the old value is 0, it cannot be defined. In comparisons where the existing values are negative, the interpretation of mathematical results and routine increases and decreases may be different.
| Purpose | input | Results |
|---|---|---|
| Value equivalent to 20% | 50,000, 20 | 10,000 |
| Price after 20% discount | 50,000, 20 | 40,000 |
| Increase from 100 to 80 | 100, 80 | −20% |
Frequently Asked Questions
If you discount 10% after a 20% discount, is it a 30% discount?
No. A 20% discount from 100 is 80, and a 10% discount here is 72, so the total discount rate is 28%.
What is the difference between percentage and percentage point?
When the ratio goes from 10% to 15%, it is a 5 percentage point increase. The increase/decrease rate over the existing ratio is 50%.
How many decimal places are displayed?
The screen displays up to 8 decimal places. Repeated calculations of rounded display values may result in errors.
Written and operated by: Moyoutil · Content review: 2026-09-30 · Error report