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Percentage Calculator
Free · No sign-up · Works in your browser
What is X% of Y?
What is% of?
X is what % of Y?
is what % of?
Percentage Change
Fromto
What percentage is X of Y?
is what % of?
How to Calculate Percentages
A percentage is a way of expressing a number as a fraction of 100. The percentage formula is: Percentage = (Part / Whole) × 100.
Our free percentage calculator handles all common percentage calculations: finding a percentage of a number, calculating percentage change between two values, and determining what percentage one number is of another.
Common Percentage Calculations
- Percentage of a number: What is 15% of 200? → 200 × 0.15 = 30
- Percentage change: From 80 to 100 → ((100-80)/80) × 100 = 25% increase
- Percentage difference: 50 out of 200 → (50/200) × 100 = 25%
Quick answer
Percentage Calculator is a free browser tool from SimpleCounter. Free online percentage calculator. Calculate percentages, percentage change, increase & decrease instantly. Easy to use, no signup required. Enter your values and the result updates as you type — there is nothing to install and no account to create.
- Definition: Percentage Calculator
- A percentage calculator takes the numbers you enter and returns the result using the standard formula for that calculation, so you do not have to work it out by hand.
Key facts
| Cost | Free, with no account and no usage limit. |
|---|---|
| Where the maths happens | In your browser. The values you type are not sent to a server. |
| Devices | Any modern browser on phone, tablet, laptop or desktop. |
| Accuracy | Standard published formulas, shown with the units you selected. |
| Intended use | Estimates for everyday and educational use, not professional advice. |
How to use the percentage calculator
- Type your value into the first field.
- Choose the unit or option that matches your figures, if the tool offers a choice.
- Read the result — it recalculates immediately, with no submit button.
- Change any input to compare a second scenario side by side.
How this page relates to the rest of the site
- Type of
- Free online tool
- Related tools
- Online counter, Online stopwatch
- Explained in
- Guides and how-tos
- Published by
- SimpleCounter
Disclaimer: This tool is provided for educational and informational purposes only. Results are estimates based on standard formulas and the inputs you provide. For financial, medical, legal, or tax decisions, consult a qualified professional. See our full disclaimer.
Frequently Asked Questions
How to calculate percentage?
To find X% of Y, multiply Y by X/100. For example, 20% of 150 = 150 × 0.20 = 30.
How to calculate percentage change?
Percentage change = ((New - Old) / |Old|) × 100. A positive result means increase, negative means decrease.
What is percentage increase formula?
Percentage increase = ((New Value - Old Value) / Old Value) × 100%.
How to find what percent one number is of another?
Divide the part by the whole and multiply by 100. For example, 25 is what percent of 200? (25/200) × 100 = 12.5%.
Benefits of using the Percentage Calculator
What you actually get compared with a mechanical clicker, a notes app, or trying to hold the number in your head.
Your count survives real life
Totals are saved on your device as you go, so a locked screen, a closed tab, or a lost signal does not reset anything.
Works offline once loaded
Install it to your home screen and it keeps working in a warehouse, a pool hall, a field, or a plane — no connection needed.
Private by default
Counts stay in your browser. There is no cloud sync, no profile, and nothing about what you count is sent to us.
Free, with no sign-up
Works offline once loaded
Counts stay on your device
Installable as an app
Runs in your browser — nothing to download
72+ counter types available
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