Percentage calculator
Calculate percentages every way: X% of Y, increase, discount and percentage change.
10% of 250
25
How the calculation works
A percentage is a fraction of 100. The most common operations:
- A% of B = (A ÷ 100) × B
- A is what % of B = (A ÷ B) × 100
- Increase = B × (1 + A/100)
- Discount = B × (1 − A/100)
- Change from A to B = ((B − A) ÷ A) × 100
Frequently asked questions
How to calculate a store discount?
Use the "Decrease B by A%" mode: B is the price and A is the discount percent.
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Updated on June 17, 2026 · by Rafael Rossi · Methodology & sources