Everyday Math
Percentage Calculator
Free percentage calculator for X% of Y, what percent X is of Y, and percentage increase or decrease between two numbers. Fast, accurate, no signup needed.
Example: What is 20% of 150?
Result
Answer 0
What is X% of Y — and is that the same as “X is what percent of Y”?
Those are different questions. 20% of 150 is an amount (30). 30 is what percent of 150 is a rate (20%). Percent change asks how far a number moved: from 80 to 100 is a 25% increase, not a 20-point increase. Pick the mode that matches the sentence you are trying to finish.
Which mode to use
| You are asking | Use |
|---|---|
| How much is 7.25% sales tax on $40? | X% of Y → 7.25% of 40 |
| I scored 42 out of 50. What percent is that? | X is what % of Y |
| Price went from $12 to $15. Up how much %? | Percent change |
Formulas
A negative percent change is a drop. For sale tags with stacked coupons, the discount calculator applies each cut in order instead of adding percents.
X% of Y = (X ÷ 100) × Y
X as % of Y = (X ÷ Y) × 100
% change = ((new − original) ÷ original) × 100
Frequently Asked Questions
How do I calculate a percentage increase?
Use the Percentage Increase / Decrease mode: enter the original value as X and the new value as Y. The calculator computes ((Y - X) / X) x 100. If the result is positive, it's an increase; the calculator labels it clearly and shows the exact percentage.
How do I calculate a percentage decrease?
Use the same Percentage Increase / Decrease mode - enter the original (higher) value as X and the new (lower) value as Y. The formula ((Y - X) / X) x 100 returns a negative number, which the calculator labels as a percentage decrease.
How do you calculate percentage change between two numbers?
Percentage change = ((New Value - Original Value) / Original Value) x 100. A positive result means the value increased; a negative result means it decreased. This calculator's third mode does this automatically and labels the direction for you.
What percent of a number - how do I find X% of Y?
Use the 'X% of Y' mode: enter the percentage as X and the number as Y. The calculator computes (X / 100) x Y. For example, 20% of 150 is (20/100) x 150 = 30.
How do I find what percentage one number is of another?
Use the 'X is what % of Y' mode: enter the part as X and the whole as Y. The calculator computes (X / Y) x 100. For example, 30 is what percent of 150? (30/150) x 100 = 20%.
Why is my percentage change showing a negative number?
A negative percentage change means the new value is lower than the original value - i.e. a decrease. The calculator explicitly labels results as 'Percentage Decrease' when this happens, and shows the magnitude of the drop.
Can percentages be greater than 100%?
Yes. In 'X% of Y' mode, a percentage above 100% simply means you're calculating more than the whole of Y (e.g. 150% of 40 = 60). In percentage change mode, an increase of more than 100% means the new value is more than double the original.
What's the difference between percentage points and percent change?
Percentage points are a simple difference between two percentages (e.g. going from 20% to 25% is a 5 percentage point increase), while percent change measures the relative change (going from 20% to 25% is a 25% relative increase, since 5/20 = 0.25). This calculator's 'percentage change' mode computes relative percent change between two plain numbers, not percentage points.
Related Calculators
About these results: Figures are for planning only. Confirm anything you will buy, bill, or submit (materials, payroll, medical screening) against the label, a quote, or a professional.