Percentage Calculator
Calculate percentages with multiple methods including visual charts and step-by-step solutions. Supports percentage of a number, what percentage, percentage change, reverse percentage, and percentage difference calculations. All processing is done in your browser for privacy.
Overview
This percentage calculator covers five distinct calculation types: finding a percentage of a number, determining what percentage one number is of another, computing percentage increase or decrease, reversing a percentage to recover the original value, and finding the percentage difference between two values. Each result comes with a visual chart, a step-by-step formula breakdown, and practical real-world examples so you can follow the math — not just copy a number. Because every calculation runs locally in your browser, nothing you enter is ever transmitted to a server, making it safe to use for sensitive figures like salaries, margins, or financial projections.
Key Features
- Calculate percentage of a number (e.g., 20% of 150)
- Find what percentage one number is of another
- Calculate percentage increase or decrease between values
- Reverse percentage calculations to find original values
- Calculate percentage difference between two values
- Visual charts and progress bars for each calculation type
- Step-by-step calculation breakdown
- Real-world examples for each calculation type
- Input validation with helpful error messages
- Mobile-responsive design with clean interface
- Instant calculations as you type
- Copy results functionality
Common Use Cases
- Discount & Markup Math — Retailers and shoppers use the "percentage of a number" mode to work out sale prices, VAT amounts, or wholesale markups without reaching for a spreadsheet.
- Growth Rate Reporting — Analysts and marketers calculate month-over-month or year-over-year percentage change for revenue, traffic, or conversion metrics and get the formula shown for reporting.
- Reverse-Engineering Original Prices — Use reverse percentage to find what a product originally cost when you only know the discounted price and the percentage off — common in expense reconciliation.
- Grade & Score Comparisons — Students and teachers use percentage difference to compare two exam scores or datasets and understand the relative gap between them.
- Commission & Profit Margin Checks — Sales teams quickly verify commission payouts or gross margins by entering the part and the whole to confirm "what percentage" one figure is of another.
How It Works
Pick a Mode
All five modes are shown at the top — percentage of a number, what percentage, percentage change, reverse percentage, or percentage difference. No menu to dig through.
Fill in the Equation
The inputs sit inside a plain-language equation that reads like a sentence, so it's obvious what each number means. Or tap a preset to fill them instantly.
Read the Result
The answer updates live as you type, with a step-by-step breakdown and a one-tap copy for the result or a shareable link.