Percentage calculator
The five most common percentage problems on one page — no formulas, no decimal slip-ups.
Runs in your browser. Nothing you enter is sent to our server.
About this tool
Discounts, VAT, mark-ups, pay rises, budget shares — they are all percentage problems. The calculator covers the five typical ones: a percentage of a number, a share as a percentage, increasing or decreasing by a percentage, and percentage change.
You can type numbers with a decimal point or comma and with thousands separators. Results are rounded to remove floating-point noise (0.1 + 0.2 = 0.3, not 0.30000000000000004).
How to use
- Find the type of problem you need.
- Enter two numbers — the answer appears immediately.
- Copy the result with the button next to it.
Examples
15% of 200
30
Change from 80 to 100
+25%
Frequently asked questions
Why don’t +10% and −10% cancel out?
The percentages apply to different bases: 100 + 10% = 110, but 110 − 10% = 99. To get back to 100 you need to decrease 110 by 9.09%.
How do I remove 20% VAT from a price?
Divide the gross price by 1.2. That is not the same as subtracting 20%: 120 − 20% = 96, while 120 / 1.2 = 100.
What is the difference between percent change and percentage points?
If a rate rises from 10% to 12%, that is +2 percentage points but a 20% increase relative to the old value.