Percentage Calculator
Three percentage solvers in one place — find a percentage of a number, work out what percent one number is of another, and calculate percentage increase or decrease.
1 · What is X% of Y?
% of
45
2 · X is what % of Y?
is what % of
15%
3 · Percentage change from X to Y
From
to
Change—
Difference—
How to use the Percentage Calculator
X% of Y: enter the percentage and the number to find the part — e.g. 15% of 300 = 45.
X is what % of Y: enter two numbers to find their ratio as a percentage.
Percentage change: enter the old and new values to see increase or decrease as a %.
Frequently asked questions
How do I calculate percentage increase?
Subtract the original value from the new value, divide by the original value, and multiply by 100: ((new − old) ÷ old) × 100.
How do I find what percent one number is of another?
Divide the first number by the second and multiply by 100. Example: 45 ÷ 300 × 100 = 15%.
Can I use decimals and negative numbers?
Yes — the calculator handles decimals, and percentage change correctly reports decreases for negative results.