Percentage Calculator
Solve all three percentage questions: X percent of Y, X is what percent of Y, and percent change. Step-by-step, instant.
Pick a question
Result
30
15% of 200 = 30
Multiply 200 by 0.15 (which is 15 percent expressed as a decimal).
Frequently Asked Questions about the Percentage Calculator
How do I calculate a percentage?
Multiply the value by the percent expressed as a decimal. For example, 20% of 50 = 0.20 x 50 = 10. The calculator handles all three common questions: X% of Y, X is what % of Y, and percent change from X to Y.
What is 20% of 100?
20% of 100 equals 20. The math: 0.20 multiplied by 100.
How do I find percent change?
Subtract the original value from the new value, divide by the original value, then multiply by 100. A positive result is an increase, a negative result is a decrease.
What is the difference between percentage and percent?
They are the same concept. Percent (sign: %) is the unit; percentage is the broader term. 50 percent and 50% mean the same thing: half of the whole.
How do I calculate a tip without this calculator?
For a 20% tip, move the decimal point one place left to get 10%, then double it. For $48.50, 10% is $4.85, so 20% is $9.70.
How do I calculate the original price before a discount?
Divide the sale price by 1 minus the discount as a decimal. A $40 item after a 20% discount: 40 / (1 - 0.20) = 40 / 0.80 = $50 original.
How accurate is this calculator?
Results are exact for values that JavaScript can represent in double-precision floating point (about 15 significant digits). Truly enormous numbers can show small rounding errors; reasonable everyday values are precise.