Percentage Calculator
Increase, discount and ratio, all on one screen
Input
Fill in whichever boxes you need — the answer appears below. The four calculations work independently.
Percentage of a value
One number as a percentage of another
Percentage change
Discounted price
Result
Percentage of a value
One number as a percentage of another
Percentage change
Discounted price
You save 11,700.
Percentage change is measured against the starting value, so a rise and a fall of the same percentage do not cancel out.
Percentages are simple until you have to do one in your head at the till. Four common calculations sit here side by side, each working independently, so you can use whichever one matches the question.
How to use
- 1 Find the calculation that matches your question.
- 2 Fill in the two boxes.
- 3 The answer appears immediately below.
- 4 The four calculations are independent — use any of them at any time.
Frequently asked questions
Why is a 50% rise not cancelled by a 50% fall?
Because each is measured against a different base. 100 up 50% is 150; 150 down 50% is 75, not 100. Percentage changes are relative to whatever came immediately before them.
How do I apply two discounts?
One after the other, not added together. 20% then 10% off is 0.8 × 0.9 = 0.72, a 28% total reduction — not 30%. Stacked discounts always come out less than their sum.
What is the difference between percent and percentage points?
A rate moving from 4% to 5% is a rise of one percentage point, but a 25% increase. Reports exploit this ambiguity constantly, so it is worth checking which one is meant.