🔬ScienceUpdated March 2026

Percentage Calculator - Find Percent of Any Number

Calculate the percentage of a number, find what percent one number is of another, or apply percent increase and decrease instantly.

%
15% of 200
30

(15 / 100) × 200

How to use this calculator

  1. 1Choose the type of percentage problem.
  2. 2Enter the values you know.
  3. 3Review the answer and formula.
  4. 4Switch between percent of a number, what percent, and percent change modes.

Written by FreeToolCalc Team

Formulas based on standard financial/medical equations. Last updated: March 2026.

Why a percentage calculator is useful

Percentage math shows up in discounts, taxes, tips, grades, raises, and business reporting. A percentage calculator saves time and helps you avoid easy mistakes.

Core percentage formulas

  • Percent of a number: (percent / 100) × number
  • What percent: (part / whole) × 100
  • Percent increase: number × (1 + percent / 100)
  • Percent decrease: number × (1 - percent / 100)

Everyday percentage examples

QuestionAnswer
15% of 20030
45 is what percent of 180?25%
Increase 250 by 12%280

Related Calculators

💹
Markup Calculator

Use percentage math for pricing

📈
Profit Margin Calculator

Work with business percentages

💵
Pay Raise Calculator

Translate raises into percent and dollars

Frequently Asked Questions

How do I determine the percentage of a number?

Multiply the number by the percentage written as a decimal. For example, 15% of 200 is 0.15 multiplied by 200, which equals 30.

What is the formula for percentage of a number?

Use this formula: result = (percent / 100) multiplied by number.

How do I calculate percent increase?

Multiply the starting number by 1 plus the percentage as a decimal. For a 10% increase, multiply by 1.10.

How do I calculate percent decrease?

Multiply the starting number by 1 minus the percentage as a decimal. For a 10% decrease, multiply by 0.90.

How do I find what percent one number is of another?

Divide the part by the whole and multiply by 100.