Percentage Calculator
Calculate a percentage, ratio, or value after a percentage change.
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20% of 150 is 30.
Calculation: 150 × (20 ÷ 100) = 30
Quick example
Common percentage calculations
Percentages are used for shares, discounts, increases, decreases, and parts of a whole. This calculator is useful for shopping, grades, fee splitting, discount checks, and simple business calculations.
Use the three modes to find a percent of a number, find what percentage a part is of the whole, or calculate a value after a percentage increase or decrease. For share-of-total calculations, the whole cannot be zero.
Formula or logic
- Part = Whole × Percentage
- Percentage = Part ÷ Whole × 100%
- Value after change = Original value × (1 ± Percentage)
Example
If an item costs 1,000 and you select a 15% decrease, the result is 850. In share-of-total mode, 150 ÷ 1,000 × 100% = 15%.
Common questions
Are percent and percentage points the same?
No. Moving from 10% to 15% is a 5 percentage-point increase, but the relative increase is 50%.
Does a 20% discount mean multiplying by 0.8?
Yes. A 20% discount means paying 80% of the original price, so final price is usually original price × 0.8.
Can this calculate share of total?
Yes. Divide the part by the whole and multiply by 100% to get the share.