Percentage Calculator

A percentage is a fraction with denominator 100. To find X% of a number, multiply the number by X/100.

To find what percent A is of B: (A / B) x 100%.

Percentage change formula: ((New - Old) / |Old|) x 100%.

Example: value changes from 50 to 80. Change = ((80-50)/50) x 100 = 60%.

Four percentage operations in one tool:

Results appear instantly — no page reload.

Shopping: Calculate sale prices after a discount. Find the final cost with tax added.

Finance: Compute interest rates, investment returns, loan payments as percentages of principal.

Education: Solve percentage word problems, calculate test scores, determine grade weights.

Business: Track revenue growth, profit margins, conversion rates, and market share.

Tipping: Find 15% or 20% of a restaurant bill in one step.

To add P% to a number N: Result = N x (1 + P/100).

Example: Add 15% to 200 = 200 x 1.15 = 230.

To subtract P% from a number N: Result = N x (1 - P/100).

Example: Subtract 15% from 200 = 200 x 0.85 = 170.

Percentage: A ratio expressed as a fraction of 100, denoted by the % sign.

Base value: The original number the percentage applies to.

Percentage of a number: The result of multiplying a number by a percentage.

Percentage change: The difference between two values expressed as a percentage of the original.

Percentage increase: Adding a percentage of the original value.

Percentage decrease: Subtracting a percentage of the original value.

Read the problem carefully: Identify whether you need a percentage of a number, a percentage change, or a comparison.

Use the right formula: Percentage of number = Number x Percent/100. Percentage change = (Difference/Original) x 100.

Order of operations: Multiply by the percentage first, then divide by 100.

Check your work: For financial calculations, verify with a second method.