CalculateMeasure

Percentage Calculator

Solve percentage problems in one place: find a percent of a number, determine what percent one number is of another, calculate percentage change, increase or decrease a value, reverse a percentage change, calculate percent error or difference, and compare percentage points.

Result
—

Percentage Formulas

X% of Y = (X ÷ 100) × Y
X is what % of Y = (X ÷ Y) × 100
Percentage change = ((New − Original) ÷ Original) × 100
Percent error = |Observed − Accepted| ÷ |Accepted| × 100
Percent difference = |A − B| ÷ ((|A| + |B|) ÷ 2) × 100
Percentage-point change = New % − Original %

Quick Examples

20% of 150 = 30. If a value changes from 100 to 125, that is a 25% increase. Increasing 200 by 15% gives 230.

Understanding Percentages

A percentage expresses a quantity per hundred. Percentage change compares the difference between a new and original value with the original value. If the original value is zero, the standard percentage-change formula is undefined.

Related Calculator

📊
Gross Margin Calculator
Use percentages in a business profitability calculation.

Calculator guide

About the Percentage Calculator

Percentage calculations compare a part with a whole or describe how one value changes relative to another.

What to keep in mind

  • Keep the part and whole in the same units.
  • A percentage can exceed 100 when the part is larger than the reference whole.
  • Percentage change and percentage of a total answer different questions.

Formula & methodology

Calculate percentages, percentage change, percentage of a number, and percentage difference.

Review standard: Level A · Standard formula. How calculator reviews work.

CalculateMeasure performs the arithmetic locally in your browser. The displayed result depends on the values and units you enter.

Frequently asked questions

What does this calculator calculate?

Percentage calculations compare a part with a whole or describe how one value changes relative to another.

Can I use the result for an important decision?

Use the result as a calculation aid and verify the inputs, assumptions, and applicable professional or regulatory requirements before relying on it for an important decision.

Does CalculateMeasure store the values I enter?

This calculator performs its arithmetic in your browser. The calculator itself does not need to send your entered values to a server to produce the result.