Calculators Featured Popular

Percentage Calculator

Calculate percentages: what is X% of Y, reverse percent, percentage change, increase or decrease by a percent.

Instant results Privacy first

Free online tool · instant results

Workspace

Your inputs

Calculation mode

Percent (%)

Of number

Ctrl + Enter Run with Control or Command and Enter

Results

No results yet

Choose a mode, enter two values, and calculate.

What it does

Calculate percentages: what is X% of Y, reverse percent, percentage change, increase or de...

Best for

Calculate percentages: what is X% of Y, reverse percent, percentage chan...

Time

~1 min to complete

Pricing

Free forever

Access

No signup required

Privacy

Runs in your browser

Overview

About this tool

A clear look at what this tool is for and why people use it.

Percentage Calculator

Calculate percentages: what is X% of Y, reverse percent, percentage change, increase or decrease by a percent.

The free Percentage Calculator on AdvanzoTools handles everyday percent math in one place. Find what a percent of a number is, learn what percentage one number is of another, measure percentage change between two values, or raise and lower a figure by a percent.

Results show a clear summary you can copy. Calculations run on demand and are not stored.

Highlights

Instant results
Private by design
Works offline-capable
Copy-ready output

Why use it

Benefits

Everything you need for a fast, confident answer — nothing you don’t.

Free to use

no signup for core calculations

Mobile-friendly workspace on a dedicated p

Mobile-friendly workspace on a dedicated page

Clear formulas and worked examples

Private

inputs are not saved by this tool

Walkthrough

How to use

Simple steps from empty form to a result you can use.

1

Enter your values in the workspace form.
2

Select Calculate to run the formula.
3

Review results; copy when available.
4

Reset clears inputs for another run.

Worked samples

Examples

Real-world scenarios so you can match the math to your situation.

Example 1

Percent of a number

15% of 240: 36.

Example 2

Percentage change

From 80 to 100 is a 25% increase.

Example 3

Increase by percent

200 increased by 10%: 220.

Under the hood

How it works

Follow the path from input to output — transparent and easy to scan.

Input

Choose a mode, enter two numbers, and calculate.

• Percent of: result

number × (percent ÷ 100)

• Is what %: percent

(part ÷ whole) × 100

• Change

((new − old) ÷ old) × 100

• Increase/decrease

number ± number × (percent ÷ 100)

Math reference

Formula

Copy the formula or inspect each variable below.

Formula

Beautiful math, ready to reuse

percent_of = n × (p / 100)
is_percent = (part / whole) × 100
change_% = ((new − old) / old) × 100
increased = n × (1 + p/100)
decreased = n × (1 − p/100)

Variables

percent_of = Percent Of n = Count / periods p = Primary value / price is_percent = Is Percent part = Part whole = Whole change_ = Change new = New old = Old increased = Increased decreased = Decreased

This formula is applied from the values you enter. Copy it for notes or spreadsheets when you need the same math offline.

Pro tips

Tips

Small habits that make this tool even more useful day to day.

Get accurate results

Double-check units and inputs before you rely on Percentage Calculator output for anything important.

Work faster

Use the examples below as a starting point, then tweak values to match your scenario.

On any device

This tool is mobile-friendly — bookmark the page so you can reopen it in one tap.

Watch out

Common mistakes

Avoid these slip-ups so your result is ready the first time.

Leaving required fields blank

Enter every value the workspace asks for before calculating — empty fields usually block a result.

Using invalid numbers

Avoid negative values or percentages outside a valid range unless the tool explicitly allows them.

Mixing up units

Keep units consistent (currency, length, weight, time) so the formula returns a meaningful answer.

FAQ

Frequently asked questions

Straight answers to the questions people ask most.

Choose “What is X% of Y”, enter the percent and the number, then calculate. The result is number × percent ÷ 100.

Select “Percentage change”, enter the original and new values. The formula is ((new − original) ÷ original) × 100.

Dividing by zero is undefined. Use a non-zero baseline or a different mode.

Yes. The Percentage Calculator is free to use without signup.

Help Build More Free Tools

Support AdvanzoTools

AdvanzoTools is built to provide fast, reliable, and free online tools for everyone.

If our tools have helped you save time or improve your workflow, you can support ongoing platform development. Your support helps improve existing tools, build new ones, maintain secure infrastructure, and keep AdvanzoTools free for everyone.

Support AdvanzoTools Learn More

History

Recently used

Pick up where you left off on this device.

Trending

Popular calculators

Other free tools people open after this page.

Calculators

Standard Calculator

Free online standard calculator for addition, subtraction, multiplication, and division — with keyboard support, memory, percent, and session history.

Open

AI Tools