Find part, share or whole
Use a percentage for a part of a number, a share of a total, or the whole when the percentage and part are known.
Everyday percentage maths
Percentage Calculator
Calculate percentages, changes, differences, percentage points and discounts. Choose the question first, then see the answer, formula and plain-English meaning.
What are you trying to figure out?
Step 1
Choose the question
Pick the calculation that matches your situation.
Step 2
Enter your values
The labels update to match the question you selected.
All calculations stay in this browser.
20% of 150
- In plain English
- 20% of 150
- Formula
- 150 × 20 / 100
How to use it
Match the calculation to the question you have.
Describe a change clearly
Use change when there is a before and after value. It reports both absolute and relative change.
Compare rates and prices
Use percentage points for rates, difference for independent values, and discount options for prices.
Useful for
Quick answers for prices, reports and everyday comparisons.
Shopping and pricing
Check a discount, compare a price change, or find the original price.
Work and school
Turn a part into a percentage or explain a result with the displayed formula.
Rates and dashboards
Separate a percentage-point movement from a relative percentage change.
Method & limits
Standard percentage arithmetic, with the context shown.
Percentage of a number
The calculator multiplies the number by the percentage divided by 100.
Change and difference
Change uses the starting value; difference uses the average of two non-negative values.
Important limits
A percentage change from zero is undefined. Signed values can make percentage difference misleading.
FAQ
Percentage Calculator FAQ
What is 20% of 150?
30. Enter the numbers and the calculator shows the formula step by step.
How do I calculate percentage increase?
Subtract the old value from the new value, divide by the old value, then multiply by 100. The calculator has a dedicated increase/decrease mode.
Any trick to calculate percentages mentally?
Try the 10% method: move the decimal point one place left, then scale the result. The page includes more mental-math tips.
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