Percentage Calculator

Free percentage calculator. Calculate percentages, percentage change, and what percent one number is of another.

👆Enter any two values to calculate the percentage

How to Use the Percentage Calculator

Choose the calculation type, enter your values, and get the result instantly. Supports: % of a number, % change, and what % X is of Y.

About This Tool

Percentages appear everywhere — sale discounts, tax rates, exam scores, investment returns, and statistical data. Despite being a simple concept (parts per hundred), percentage calculations are one of the most commonly searched math operations online because the phrasing can be confusing: 'what is 15% of 80?' and '12 is what percent of 150?' require different formulas. This calculator handles three types: finding a percentage of a number, finding what percentage one number is of another, and calculating percentage change (increase or decrease) between two values. Results update instantly. Pair with the Tip Calculator for restaurant math or the Loan Calculator for financial planning.

Quick Reference Table

Percentage	of 1,000
5%	50
10%	100
15%	150
20%	200
25%	250
30%	300
50%	500
75%	750

Frequently Asked Questions

How is a percentage calculated?

To find X% of a number, multiply the number by X and divide by 100. For percentage change, the formula is ((new − old) / old) × 100.

Is my data safe?

Yes. All calculations run entirely in your browser. No data is sent to any server, stored, or accessible to anyone but you.

How accurate are the results?

The calculator uses standard JavaScript floating-point arithmetic (IEEE 754 double precision), which is accurate to 15–17 significant digits. This exceeds the precision needed for any practical percentage calculation.

Is this calculator free to use?

Yes. Completely free, no signup required.

How do I calculate a discount price?

Multiply the original price by (1 − discount/100). For example, 25% off a $80 item: $80 × (1 − 0.25) = $80 × 0.75 = $60. This calculator automates this by showing you X% of a number directly — enter 25 and 80 to get 20 (the discount), then subtract from the original.