Use our free percentage calculator to find a percentage of a number, calculate percentage change, compare two values, or work out a discount. Choose the form that matches your question and enter the known values.
How to calculate X percent of Y?
For example, 5% of 200 is 10.
How much percent of X is Y?
For example, 20 is 40% of 50.
How to calculate the percentage difference between X and Y?
For example, the percentage difference between 12 and 10 is approximately 18.18%, using their average as the reference value.
How do you determine the percentage change from X to Y?
For example, a change from 4 to 5 is a 25% increase.
How to calculate percentage increase/decrease?
For example, 10 increased by 10% is 11.
How to add or subtract a percentage?
For example, subtracting 50% of 20 from 20 gives 10.
How to calculate the percent off?
For example, a 30% discount on $99.99 gives a final price of $69.99, rounded to the nearest cent.
How to find your percentage test score?
For example, if you earn 150 points out of a possible 200, your test score is 75%.
How to use our calculator?
Select the calculation you need, enter your numbers, and read the result. For a percentage of a number, enter the percentage and the total. To find what percent one number is of another, enter the part and the total.
For percentage change, enter the original value first and the new value second. The order matters: a rise from 50 to 100 is a 100% increase, but a fall from 100 to 50 is a 50% decrease.
Enter percentages as ordinary numbers in percentage fields: use 10 for 10%, not 0.10. When calculating manually, convert 10% to its decimal form, 0.10, before multiplying.
Choose percentage difference when neither number is the starting value. Choose percentage change when you want to measure an increase or decrease from an original value.
If you need a similar calculator for your own pricing or forms, you can build one with our no-code form builder with calculations.
What is the percentage?
A percentage expresses a number as a fraction of 100. One percent means one hundredth: 1% = 1/100 = 0.01. Percentages make it easier to compare proportions, even when the totals differ.
For example, 25 out of 100 and 50 out of 200 both equal 25%. The counts differ, but each represents the same share of its total.
The same proportion can be expressed in several forms:
- Using the % sign: 5%
- As a decimal: 0.05
- As a fraction: 5/100
All three examples represent the same value. In a calculation, use either the percentage notation or its decimal equivalent consistently: 5% of 200 is 0.05 * 200.
What is the percentage point?
A percentage point measures the absolute difference between two percentages. A percent change measures that difference relative to the original percentage.
For example, a rate rising from 10% to 12% increases by 2 percentage points, but its relative percentage increase is 20%.
One percentage point is a difference of 0.01 in decimal form. A 1% increase, by contrast, means multiplying the original value by 1.01.
For another example, assume your bank account pays 1% interest annually. If the bank increases the interest rate:
- By 1 percent, the interest rate becomes 1.01% (1% * 1.01).
- By one percentage point, the interest rate becomes 2% (1% + 1 percentage point).
In the second case, the interest rate doubles. Distinguishing percentages from percentage points is particularly useful when comparing interest rates, tax rates, and margins.
What's the percentage formula?
To calculate a percentage of a number, multiply the number by the percentage divided by 100:
result = number * percentage / 100
For example:
What is 5% of 200?
200 * 5 / 100 = 10
Here, 200 is the total, 5 is the percentage, and 10 is the resulting part of the total.
How to calculate the percentage?
The formula depends on what you need to find: a part, a percentage, a change, or a difference. The examples below show the calculation for each case.
How do you work out percentages?
Start by identifying the total, or reference value. Then convert the percentage to a decimal if needed: 5% is 5/100, or 0.05. To find a part, multiply the total by that decimal. To find a percentage, divide the part by the total and multiply by 100.
How to convert a percentage to a decimal?
Divide the percentage by 100 and remove the % sign. For example: 12.3% = 12.3 / 100 = 0.123.
How to convert a decimal to a percentage?
Multiply the decimal by 100 and add the % sign. For example:
0.123 = 12.3%
Converting fraction to a percentage value
Divide the numerator by the denominator, then multiply the result by 100 to get the percentage. Alternatively, rewrite the fraction with a denominator of 100 when that is convenient.
For example:
⅘ = (4 * 20) / (5 * 20) = 80 / 100 = 80%
How do I calculate x percent of y?
Example: What is 10 percent of 50?
Formula: result = (x / 100) * y
Where:
- x is the percentage, in this case 10.
- y is the total, in this case 50.
- Convert 10% to a decimal: 10 / 100 = 0.10.
- 0.10 * 50 = 5
- So 10% of 50 equals 5.
How much percent of x is y?
To find what percentage one number is of another, divide the part by the total and multiply by 100.
Example: What percent of 50 is 5?
Formula: percentage = (y / x) * 100
Where:
- x is the total or reference value, in this case 50.
- y is the part, in this case 5.
- The result is the percentage; add the % sign.
(5 / 50) * 100 = 10, so 5 is 10% of 50.
How do you find percentage change from x to y?
Example: What is the percentage change from 5 to 20?
Percentage change formula: C = ((y - x) / x) * 100, expressed as a percentage.
Where:
- C is the percentage change.
- y is the final value.
- x is the original value.
- A positive result indicates an increase; a negative result indicates a decrease, assuming a positive original value.
In this case:
Subtract the original value from the new value, divide by the original value, then multiply by 100.
C = ((20 - 5) / 5) * 100 = 300, so the increase is 300%.
For a decrease from 20 to 5, the calculation is ((5 - 20) / 20) * 100 = -75, or a 75% decrease. Percentage change is undefined when the original value is zero.
How to find the percentage difference between two numbers?
Use percentage difference to compare two nonnegative values when neither is the original or reference value. Divide their absolute difference by their average:
D = |X - Y| / ((X + Y) / 2) * 100, expressed as a percentage.
Where:
- D is the percentage difference.
- |X - Y| is the absolute difference between the two numbers.
Unlike percentage change, this calculation gives the same result regardless of the order of the two values. The formula is undefined when their average is zero.
Example: What is the percentage difference between 200 and 50?
D = |200 - 50| / ((200 + 50) / 2) * 100 = 150 / 125 * 100 = 120%.
Compounding percentages
Repeated percentage changes apply to the latest value, not the original amount. For example, start with 1,000 and increase it by 10% each year:
Year 1: 1,000 * 1.10 = 1,100
Year 2: 1,100 * 1.10 = 1,210
Year 3: 1,210 * 1.10 = 1,331
Year 4: 1,331 * 1.10 = 1,464.10
The percentage stays the same, but the amount added grows each year. The steps above can be written as:
1,000 * 1.10⁴ = 1,464.10
Four increases of 10% produce a total increase of 46.41%, not 40%. Similarly, a 10% increase followed by a 10% decrease does not return you to the starting value: 100 * 1.10 * 0.90 = 99.
In finance, repeated growth is described by the compound interest formula:
Where:
- A is the final amount.
- P is the initial amount, or principal.
- r is the annual interest rate expressed as a decimal, such as 0.10 for 10%.
- n is the number of times interest is compounded per year.
- t is the number of years.
You can find a more detailed explanation of this concept in our compound interest calculator.
Real-life applications
Store discounts: 30% off sale
To calculate a sale price, subtract the discount percentage from 100%, then multiply the original price by the remaining percentage.
For example, an item priced at $129.99 with a 30% discount costs:
$129.99 * (1 - 30 / 100) = $129.99 * 0.70 = $90.99, rounded to the nearest cent.
The saving is $39.00 after rounding. To increase a price instead, use new price = original price * (1 + percentage / 100).
Taxes
To add sales tax to a price before tax, multiply that price by one plus the tax rate in decimal form. For example, with a net price of $10 and a tax rate of 20%:
Gross price = net price * (1 + tax rate / 100) = $10 * 1.20 = $12.
To work backward from a tax-inclusive price, divide by the same multiplier: $12 / 1.20 = $10 before tax. Subtracting 20% from $12 would not give the correct net price.
Helpful tools
When calculating percentages of money, keep full precision during the calculation and round the final result as needed. To adjust a result to a more round and readable value, use a rounding tool. For larger amounts, our rounding money calculator lets you round to the nearest dollar, hundred, or thousand.
For a reliable percentage calculation, identify the reference value first. Use the total for a percentage of a number, the original value for percentage change, and the average of the two values for percentage difference.