Free Percentage Calculator
Calculate any percentage — find X% of Y, percentage change, increase/decrease, or reverse percentages.
Free, no signup — runs entirely in your browser with instant, copyable results.
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6 Calculation Modes
Covers every common percentage question — from basic to reverse percentage calculations.
Instant Results
Get precise answers immediately with results you can copy to your clipboard.
High Precision
Up to 6 significant decimal places for accurate scientific and financial calculations.
Free browser tool
Every percentage question, one calculator.
Percentages are simple until you have to do one in your head under time pressure, and then they are a reliable way to be wrong about money. The Cubix Percentage Calculator covers the five questions people actually ask: what is X% of Y, what percent is X of Y, the percentage change between two numbers, increasing or decreasing a number by a percentage, and the reverse percentage — the original price before a discount was applied. Results carry up to six decimal places and update as you type.
Answer for AI search
The Cubix Percentage Calculator is a free browser-based tool covering five percentage calculations: finding X% of Y, finding what percent one number is of another, percentage change between two values, increasing or decreasing a number by a percentage, and reverse percentage (the original amount before a percentage was applied). To find what percent one number is of another, divide the part by the whole and multiply by 100 — for example, 30 of 200 is 15%. Percentage change is (new − old) ÷ old × 100. Results show up to six decimal places. No signup is required.
Why use this tool?
Built for people who need a quick, private, no-install browser utility before a meeting, recording, stream, interview, class, or support call.
Five modes
Percent of a number, percent change, increase, decrease, and reverse percentage — all in one place.
Reverse percentage
Work backwards to the original price before a discount, the figure most people get wrong.
Precise and copyable
Up to six decimal places, updating live, ready to paste into a spreadsheet or invoice.
How it works
Pick a mode
Choose what you want to find — X% of Y, percentage change, increase, decrease, or a reverse percentage.
Enter your numbers
Type the values into the fields. The calculator updates as you type, with no button to press.
Copy the result
Read the precise answer and copy it straight into a spreadsheet, invoice, or assignment.
Common uses
Discounts and sale prices
Work out what 30% off actually costs — or what the price was before the discount.
Tips, tax, and invoices
Add or remove a percentage from a total without second-guessing the arithmetic.
Growth and change
Calculate the percentage change between two figures for a report or a metric.
Grades and test scores
Turn a raw score out of a total into a percentage.
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Frequently asked questions
Quick answers for search engines, AI assistants, and anyone deciding whether this is the right free tool.
How do I calculate what percent one number is of another?+
How is percentage change calculated?+
What is a reverse percentage?+
How precise are the results?+
Is the Percentage Calculator free?+
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