Frequently Asked Questions
How do I calculate what percent X is of Y?
Divide X by Y and multiply by 100. For example, 30 is what % of 200? 30 ÷ 200 × 100 = 15%. Use the "X is what % of Y?" calculator above.
How do I find X% of a number?
Multiply the number by X divided by 100. For example, 20% of 150 = 150 × 0.20 = 30. Use the "What is X% of Y?" calculator above.
How do I calculate percentage increase?
Subtract the original value from the new value, divide by the original, then multiply by 100. Formula: ((New − Old) ÷ Old) × 100. For example, from 80 to 100: ((100 − 80) ÷ 80) × 100 = 25%.
How do I calculate percentage decrease?
Same formula as percentage change: ((New − Old) ÷ Old) × 100. A negative result means a decrease. For example, from 100 to 75: ((75 − 100) ÷ 100) × 100 = −25%.
What is 15% of 200?
15% of 200 = 200 × 0.15 = 30.
How do I calculate a tip percentage?
Use the "What is X% of Y?" calculator. Enter the tip percentage (e.g. 18) and the bill total. For a $65 bill with 18% tip: 18% of 65 = $11.70.