Percentage Calculator

Figure out percentages the easy way. No complicated math needed - just plug in your numbers and get your answer.

Percentage Problem

What is X% of Y?
X is what % of Y?
X is Y% of what?
% increase/decrease
%

What is 10% of 100?

10 out of 100

25 is what % of 80?

25 out of 80

15 is 75% of what?

Find the whole

50 to 150 increase

Percentage change

Quick Tip

Remember: "percent" means "per hundred." So 25% is just 25 out of 100, or 0.25. That is all there is to it.

15% of 200 is
30
15% means 15 out of every 100. So 15% of 200 is 30.
As a fraction
3/10
As a decimal
0.15
Calculation
200 × 0.15
Ratio
15:100
15%
15% (30)
85% (170)

How it works

To find 15% of 200, you convert 15% to a decimal (0.15) and multiply it by 200. That gives you 30.

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What is the Deal with Percentages?

Percentages are everywhere - in store discounts, on tests, in statistics, you name it. But a lot of people get tripped up by them. The thing is, percentages are just fractions with 100 as the denominator. That is it. The word "percent" literally means "per hundred." So 25% is just 25 out of 100, or 25/100, which simplifies to 1/4.

How to Calculate Percentages Without a Calculator

You can do a lot of percentage math in your head if you know a few tricks. For example, to find 10% of anything, just move the decimal point one place to the left. So 10% of 250 is 25.0, or just 25. Need 20%? That is just double 10%, so 20% of 250 is 50. Need 5%? That is half of 10%, so 5% of 250 is 12.5.

For 25%, That is a quarter, so you can just divide by 4. 25% of 200 is 200 ÷ 4 = 50. For 50%, That is half, so divide by 2. 50% of 200 is 100.

Common Percentage Situations You'll Run Into

Why Percentages Can Be Tricky

The biggest mistake people make is confusing "percentage of" with "percentage increase." If something increases from 50 to 75, That is a 50% increase (because 25 is 50% of 50). But 75 is 150% of 50. See the difference? One's talking about the increase (25), the other's talking about the final amount (75).

Another common mix-up: if you get 20% off, then another 10% off, That is not 30% off total. The second 10% is off the already-reduced price, so you end up with 28% off total. Math can be sneaky like that.

Questions People Usually Ask

Here are answers to some common questions about percentages

How do I calculate a percentage?
it is pretty simple: just divide the part by the whole, then multiply by 100. So if you want to know what percent 25 is of 100, you do 25 ÷ 100 = 0.25, then 0.25 × 100 = 25%. That is 25%.
How do I find what percent one number is of another?
Take the first number (the part), divide it by the second number (the whole), then multiply by 100. Like if you have 15 out of 60, do 15 ÷ 60 = 0.25, then 0.25 × 100 = 25%. So 15 is 25% of 60.
How do I calculate percentage increase or decrease?
First, subtract the old value from the new value. Then divide that difference by the old value. Multiply by 100, and you have got your percentage change. If it is positive, it is an increase; negative means a decrease. Like if a price goes from $50 to $75, the increase is $25, divided by $50 is 0.5, times 100 is 50%. So That is a 50% increase.
What is the difference between percentage points and percent?
Good question - a lot of people mix these up. If something goes from 10% to 15%, That is a 5 percentage point increase (15 - 10 = 5). But it is a 50% increase because 5 is 50% of 10. So percentage points are just simple subtraction, while percent change is relative to the starting value.
How do I add or subtract percentages?
Be careful with this one. You can not just add percentages together unless they are percentages of the same thing. If you get 20% off, then another 10% off, That is not 30% off total. The second discount applies to the already-reduced price. So you'd calculate 20% off first, then take 10% off that new price. Or multiply the original price by 0.8 (for 20% off), then by 0.9 (for 10% off).
How do I reverse a percentage?
Let is say you know the discounted price and the discount percentage, and you want to find the original price. If something is $75 after a 25% discount, that means $75 is 75% of the original price (because 100% - 25% = 75%). So you divide $75 by 0.75 to get $100. The original price was $100.