Percentage Calculator
The percentage calculator handles the three questions people actually ask: what is A% of B, A is what percent of B, and the percentage increase or decrease from A to B. Pick the mode, enter two numbers, and the answer is computed instantly in your browser.
Calculator
The formula
- A% of B = (A ÷ 100) × B
- A is what % of B = (A ÷ B) × 100
- % change A → B = ( (B − A) ÷ |A| ) × 100 (positive is an increase, negative a decrease)
Worked example
In “What is A% of B” mode, A = 15 and B = 200 gives 30 (15% of 200). Switch to “percentage change” with A = 200 and B = 260 to get a 30% increase.
Frequently asked questions
- What does “percentage change” use as the base?
- The change is measured relative to the starting value A: (B − A) ÷ |A| × 100. Going from 200 to 260 is a 30% increase.
- Can it show a decrease?
- Yes — if B is smaller than A the change is negative and the result is flagged as a decrease.
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