Sales discounts, pay rises, price rises and test scores all come down to percentages. This calculator answers the four questions people ask most, so you do not have to remember the sums. Fill in whichever box pair you need.
The Four Questions
"What is 15% of 80?" gives you the discount on an £80 item. "18 is what percentage of 75?" is for marks, scores and shares. "Increase 200 by 5%" is for a price rise or pay rise, and works for decreases too. "From 50 to 65" shows how much something has gone up or down as a percentage of where it started.
Worked Examples
15% of 80 is 12. 18 out of 75 is 24%. 200 increased by 5% is 210. A change from 50 to 65 is an increase of 30%.
Questions about Percentage Calculator
How do I work out a percentage of a number?
Divide the percentage by 100 and multiply by the number. For 15% of 80, that is 0.15 multiplied by 80, which is 12.
How do I work out percentage change?
Subtract the old number from the new one, divide by the old number and multiply by 100. Going from 50 to 65 is a rise of 15, which is 30% of 50.
Why is a 10% rise followed by a 10% fall not back where I started?
The fall is 10% of a bigger number, so it takes off more than the rise added. 100 rises to 110, then falls by 11 to 99.