Percentage Calculator

Overview

Work out any everyday percentage: a percent of a number, what percent one number is of another, increase or decrease, the original value before a change, or the difference between two values. Each answer shows the steps, so you can follow the math instead of just copying a number. It runs in your browser, so salaries and margins stay private.

Discounts and markupsWork out sale prices, VAT or wholesale markups without opening a spreadsheet.
Growth reportsGet month-over-month or year-over-year change for revenue or traffic, with the formula to show.
Finding the original priceUse reverse percentage to get the price before a discount, handy when checking expenses.
Comparing scoresUse percentage difference to see how far apart two exam scores or figures are.
Commission and marginsEnter the part and the whole to check what percent a commission or margin really is.

Key features

Percentage of a number (20% of 150)
What percent one number is of another
Percentage increase or decrease
Reverse percentage to find the original
Percentage difference between two values
Progress bar that shows the ratio
Step-by-step working
Presets to try each mode
Clear error messages for impossible inputs
Works on phones and desktops
Results update as you type
Copy the result in one tap

Set

Calculate Tools 03

Neighbours

01 BMI Calculator 02 VAT Calculator 03 Audio Transcriber 04 Run AI in the browser 05 Invoice Builder 06 Markdown Editor & Live Preview

Specification

Command: calculate.percentage_calculator
Set: Calculate
Input: text
Output: —
Max file: no limit
Batch: single file

Runtime

Engine: native
Threads: single
Isolated: —
WebGPU: —
Memory: —

Transport 0 B

Your file is opened, worked on and saved inside this tab. This tool has no upload step, so your file has nowhere else to go.

Keys

Search: ⌘K
Panels: ⌘1 · ⌘2
Full width: F
All keys: ⌘/

How it works

Pick a mode

All five modes sit at the top, so there's no menu to dig through.

Fill in the sentence

Type your numbers into an equation that reads like a sentence, or tap a preset.

Read the result

The answer updates as you type, with the steps shown and one-tap copy or share.

Frequently asked

What types of percentage calculations can I perform?

Five: a percentage of a number (20% of 150), what percent one number is of another, percentage increase or decrease, reverse percentage to find the original value, and the percentage difference between two values.

How do I calculate percentage change?

Enter the original value and the new value. You get the increase or decrease, worked out as ((new value − original value) / original value) × 100.

What is reverse percentage calculation?

It finds the original value when you know the result and the percentage. For example, if 120 is 80% of a number, that number is 150.

Is my data kept private?

Yes. Every calculation runs in your browser, and nothing you type is sent to a server.

Can I use this for business calculations?

Yes. It works well for discounts, markups, profit margins, growth rates, commission and tax.

Keys

Search: ⌘K
Panels: ⌘1 · ⌘2
Full width: F
All keys: ⌘/