How the percentage calculator works
Three different questions, three different formulas:
% of a number: Result = (Percentage ÷ 100) × Number
X is what % of Y: Result = (X ÷ Y) × 100
% change from A to B: Result = ((B − A) ÷ A) × 100
X is what % of Y: Result = (X ÷ Y) × 100
% change from A to B: Result = ((B − A) ÷ A) × 100
Step-by-step guide
- Choose which type of percentage problem you're solving.
- Enter the two numbers involved.
- Read the result instantly as you type.
Common uses
- Calculating a discount: 20% off ₹150 uses the "% of a number" mode.
- Grading a test: 30 correct out of 150 questions uses "X is what %" mode.
- Comparing prices or metrics over time: use "% change" mode.
Frequently asked questions
Use the '% change' mode: enter the original value as 'From' and the new value as 'To'. A positive result is an increase; a negative result is a decrease.
Divide X by Y and multiply by 100 — for example, 30 out of 150 is (30 ÷ 150) × 100 = 20%.
Yes, when using percentage change mode: a decrease from a higher to lower value produces a negative percentage, indicating the size of the drop.