Percentage Calculator
Calculate percentages three ways: X% of Y, percentage change, or what percent X is of Y.
How this is calculated
X% of Y = (X/100)×Y | % change = (Y−X)/|X|×100 | X is what % of Y = (X/Y)×100
Frequently Asked Questions About Percentage Calculator
A percentage calculator solves three common percentage problems: finding X% of Y, calculating percentage change between two values, and determining what percent one number is of another.
How do I calculate X% of Y?
Multiply Y by the percentage as a decimal. For example, 15% of 200 = 200 × 0.15 = 30. The formula is: (X/100) × Y. This is useful for calculating discounts, tips, commissions, and tax amounts.
What is percentage change and how do I calculate it?
Percentage change shows how much something increased or decreased. Formula: ((new value − old value) / old value) × 100. For example, if a price goes from $100 to $120, that's a 20% increase. Negative percentages indicate decreases.
How do I find what percent one number is of another?
Divide the part by the whole and multiply by 100. For example, 25 out of 200 is (25/200) × 100 = 12.5%. This is useful for calculating grade percentages, market share, and proportions.
What's the difference between percent and percentage point?
These terms are often confused. If something goes from 10% to 15%, that's a 5 percentage point increase, but a 50% relative increase (5/10). Most people mean percentage points when discussing increases/decreases of percentages.
How do I calculate a discount?
Multiply the original price by the discount percentage. For example, 20% off $100 = $100 × 0.20 = $20 discount, so final price = $100 − $20 = $80. Or use this calculator with "X% of Y" mode.
How do I calculate percentage increase needed to return to original value?
A 50% decrease requires a larger percentage increase to recover. If $100 drops 50% to $50, you need a 100% increase to get back to $100. The required increase percentage is not the same as the decrease percentage for this reason.