Percentage Calculator Online — Free Tool

Easily compute precise percentages, find the percentage of a specific number, or determine percentage changes.

Percentage of a number

What is 25% of 200?

Percent (%)

Number

Result: 50

What percent?

25 is what percent of 200?

Result: 12.5%

Percentage change

Calculate increase/decrease from X to Y.

X (original)

Y (new)

Increase: 60%

Decrease: -60%

Privacy note: All processing happens entirely in your browser. No data is sent to our servers.

About this tool

Percentages express parts per hundred. Calculate what percent X is of Y, find a percent of a number, or measure percent increase and decrease between two values.

Results update as you type—useful for discounts, growth metrics, grades, and tip math.

Common use cases

Finding what percent one number is of another
Computing X% of a total for allocations
Measuring month-over-month growth rates
Validating spreadsheet percentage columns

How to use

Select the calculation mode you need (of, increase, decrease, etc.).
Enter the known values in the labeled fields.
Read the computed percentage or resulting amount.
Change inputs to compare scenarios side by side.

This page is available at /tools/percentage-calculator/.

Understanding the result

Percent of: result = (part ÷ whole) × 100. Whole must be non-zero.
Percent increase: ((new − old) ÷ old) × 100. Negative results mean decrease.
Applying X% to N: result = N × (X/100).
Round display decimals for reporting but keep full precision for chained calculations.