Calculator
Enter your values and read the result.
30
15% of 200 is 30
Other calculations
Runs in your browser. Your entries are calculated on this device. Ziannah does not store the values you enter here.
Calculator
Percentage Calculator
A free online percentage calculator. Work out a percent of a number, a percentage increase or decrease, percent change, or the difference between two values.
Pick the calculation you need
Each calculation has its own page with the formula, the steps, and a worked example.
The percentage formulas
Almost every percentage question is one of these three. The hard part is usually deciding which one you are being asked, not doing the arithmetic.
- Percentage increase or decrease
- (new − original) ÷ original × 100
- 40 to 46 is 6 ÷ 40 × 100 = a 15% increase
The mistake that costs people money
Percentages are always a share of something, and the answer changes when that something changes. Dividing by the wrong number is the usual error. For an increase or a decrease, divide by the value you started from, never by the value you ended with. Going from 40 to 50 is a 25% increase, because the rise of 10 is measured against 40. Measured against 50 you would get 20%, which is the answer to a different question.
Common questions
How do you calculate a percentage?
It depends which question you are asking. To find a percent of a number, divide the percent by 100 and multiply. To find what percent one number is of another, divide the part by the whole and multiply by 100.
How do you calculate percentage increase?
Subtract the original value from the new one, divide by the original value, then multiply by 100. Going from 40 to 46 is a 15% increase.
What is the difference between percentage change and percentage difference?
Percentage change measures against the value you started from and has a direction. Percentage difference compares two values against their average, so it has no direction and the order does not matter.
Why do a 20% decrease and a 20% increase not cancel out?
Because the second percentage is taken from a different number. Drop 100 by 20% and you get 80. Raise 80 by 20% and you get 96, not 100.
Is the percentage calculator free?
Yes. It is free to use online, needs no account, and the working happens in your browser so nothing you enter is uploaded.
Related reading
Read the blog
Article
Is overtime taxed more? No, and here is the real reason
Overtime is taxed at the same rate as your normal pay. Here is why your payslip looks wrong, and the new deduction that cuts what you owe from 2025 to 2028.
Article
How to Calculate Overtime Pay (Time and a Half)
Multiply your regular rate by 1.5 and then by your overtime hours. The hard part is knowing which rate to use, because it is often higher than your wage.
Article
Minutes to Decimal Hours: Payroll Conversion Chart
Divide minutes by 60. Here is the chart, the four values worth memorizing, and the rounding habit that quietly costs you minutes every week.