Percentage Calculator
Runs locally in your browser. Nothing leaves your device.Calculate percentages, parts, whole values, adjustments, and percentage changes instantly in your browser.
Whole, percentage, and part
Edit any two fields. The third is calculated automatically.
Enter two values to start the linked percentage calculation.
Compare values
Enter a starting value and a new value. The change is calculated instantly.
Calculation steps
Δ = N − A Δ = 100 − 80 Δ = +20 % = Δ / |A| × 100 % = 20 / |80| × 100 % = +25 %
How it works
- 1
Choose the calculation
Choose whether you want to calculate a percentage value, part, total, increase, discount, or change.
- 2
Enter values
Enter the known numbers. The calculator accepts localized decimal separators and updates the result immediately.
- 3
Check the steps
Use the formula, intermediate steps, and result to verify or share the calculation.
Good to know
The percentage calculator combines the most common percentage tasks in one tool: percentage value, base value, share, markup, discount, and percentage change. It is useful for prices, taxes, statistics, school work, quotes, margins, and quick plausibility checks.
Calculation runs locally in the browser and shows formula, values, and steps in a traceable way.
Typical use cases
Check prices, discounts, and markups
Quickly calculate how much a discount saves, which final price follows a markup, or which percentage share is included in a quote.
Understand shares and base values
Use the calculator for questions such as “What percent is 18 of 240?” or “Which base value corresponds to 35 percent and 70 units?”
Document the calculation path
Formula and substituted values help reuse results traceably in homework, spreadsheets, quotes, emails, or internal notes.
Tips for better results
Do not mix up base and percentage value
The base value is the reference amount; the percentage value is the calculated share. A wrong reference immediately creates wrong percentages.
Check the start value for changes
A change from 50 to 100 is plus 100 percent; from 100 to 50 is minus 50 percent. Percentage changes are not symmetric.
Features
All common cases in one calculator
Calculate part, total, percentage, markup, discount, and percentage change without switching between tools.
Instant results
As you type, the calculator updates the result, formula, and calculation steps automatically.
Local and no upload
All input stays on your device. The percentage calculator runs directly in the browser and also works offline after loading.
Traceable calculation steps
The formula and substituted values are shown so the result is more than just a number.
Frequently asked questions
What is the percentage calculator for?
It is useful for everyday calculations such as discounts, markups, shares, totals, and percentage changes.
Are my inputs stored or uploaded?
No. The calculation runs locally in the browser. There is no upload and no account.
Can I use a comma as decimal separator?
Yes. Localized routes accept their usual decimal separators; period values also work.
More tools
Looking for another tool?
Every tool runs locally in your browser – no sign-up, no upload, and it works offline.