About the Percentage Calculator
A percentage is a ratio expressed as parts per hundred. This calculator collects the four percentage questions people ask most often, from working out a 15% tip to comparing last yearโs sales with this yearโs. Results appear as you type, and you can paste numbers with thousands separators.
How to use
- Pick the box (โ to โฃ) that matches your question.
- Type your numbers. The result appears right below.
- In โฃ, tap Increase or Decrease to switch direction.
Percentage formulas
| Question | Formula | Example |
|---|---|---|
| B% of A | A ร B รท 100 | 15% of 200 = 30 |
| A is what % of B | A รท B ร 100 | 30 is 15% of 200 |
| Change from A to B | (B โ A) รท A ร 100 | 100 โ 150 = 50% increase |
| Increase A by B% | A ร (1 + B รท 100) | 10,000 + 10% = 11,000 |
Percent vs. percentage points
If an interest rate rises from 2% to 3%, it went up by 1 percentage point, but in relative terms it rose by 50%. News reports on interest rates, polls and unemployment use percentage points for the absolute difference between two percentages. Mixing the two up can make a change sound much larger or smaller than it is.
FAQ
If I increase a number by 10% and then decrease it by 10%, do I get the original number?
No. 100 increased by 10% is 110, and 110 decreased by 10% is 99. The decrease is taken from the larger number, so you end up 1% lower.
How do I calculate a discount percentage?
Enter the original price and the sale price in โข. The percentage decrease is the discount. For stacked discounts, use the discount calculator.
How do I calculate percentage increase?
Subtract the old value from the new value, divide by the old value and multiply by 100. Box โข does this for you and also shows the difference.
How many decimal places are shown?
Results are rounded to four decimal places.