How do I find a percentage of a number?

Multiply the number by the percentage and divide by 100. For example, 20% of 250 is 50.

How do I calculate a percentage increase?

Find the percentage amount and add it to the starting value, or multiply the start by one plus the rate as a decimal.

How do I calculate a percentage decrease or discount?

Find the percentage amount and subtract it from the starting value. For example, 200 after a 15% discount is 170.

Are percentage difference and percentage change the same?

No. Percentage difference treats both values symmetrically, while percentage change uses one specific value as the starting point.

How is percentage difference between two numbers calculated?

Divide the absolute difference by the average of the two absolute values, then multiply by 100.

How do I find the value before an increase?

Divide the final value by one plus the increase rate as a decimal. A final value of 120 after a 20% increase started at 100.

How do I recover the original value after a decrease?

Divide the final value by one minus the decrease rate as a decimal. An original value cannot be uniquely recovered after a 100% decrease.

Can I calculate percentages with decimal numbers?

Yes. The calculator accepts decimal values using the locale-appropriate decimal separator.

Tools/🧮 Calculators/Percentage Calculator

Percentage Calculator

Calculate percentages, increases, decreases, percentage difference, and original values.

Version 1.0 · Last Updated: August 7, 2026 · Maintained by ToolLarder

Online percentage calculations

This percentage calculator combines six common calculations used for discounts, price changes, salary increases, comparisons, commissions, and everyday arithmetic. You can also find what percentage one number is of another.

Percentage of a number

Find a specified percentage of any amount for discounts, commissions, tax portions, proportions, and other everyday calculations.

Number × percentage ÷ 100

What percentage is one number of another?

Calculate the first number as a percentage of the second. For example, 20 is 10% of 200.

First number ÷ second number × 100

Percentage increase calculator

Calculate a value after a percentage increase and see the amount added. Useful for raises, price increases, and growth calculations.

Start × (1 + rate ÷ 100)

Percentage decrease and discount

Calculate the new value after a discount or reduction and see how much was subtracted from the starting value.

Start × (1 − rate ÷ 100)

Percentage difference between two numbers

Compare two values symmetrically without treating either one as the starting value. Useful for measurement and price comparisons.

|A − B| ÷ ((|A| + |B|) ÷ 2) × 100

Original value before a percentage change

Work backward from a final value and a known increase or decrease rate to calculate the original starting amount.

Final value ÷ (1 ± rate ÷ 100)

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