Find percentages of numbers, calculate discounts, percentage change, increase/decrease, and more. Six calculation modes for every real-world percentage problem — from GST to exam marks to salary hikes.
⚡ All calculations happen instantly in your browser. Zero data stored.
The Percentage Calculator by WorldOfTools is a free, comprehensive, and multi-mode online utility that solves any percentage-related problem instantly. From calculating exam scores and shopping discounts to analyzing salary hikes, GST, business margins, and stock market returns — this tool is designed to cover every possible percentage scenario in a single, intuitive interface.
Our tool integrates six core mathematical formulas: finding the percentage of a number, calculating what percentage one number is of another, determining percentage change (increase or decrease), finding percentage difference, reversing a percentage calculation, and applying discounts. All processing occurs securely within your browser, ensuring lightning-fast results and complete data privacy with no server uploads required.
Mathematics can be complex, but our tool simplifies it into six distinct modes tailored to real-world applications:
% of Number — Find out what a specific percentage of a total number is. Example: 20% of 500 = 100. Ideal for calculating tips, specific tax amounts, or finding a portion of a whole.
X is % of Y — Determine what percentage one number represents compared to another. Example: 30 out of 150 = 20%. Perfect for calculating academic grades, attendance records, or task completion rates.
% Change (Increase / Decrease) — Measure the growth or reduction between two values. Example: A stock goes from 800 to 1000, representing a 25% increase. Essential for salary hikes, inflation, and sales analysis.
% Difference — Compare two independent values symmetrically. Used extensively in scientific experiments, A/B testing, and comparing prices of two different items where neither is a baseline.
Reverse % — Work backward to find the original number when you only know a partial value and its corresponding percentage. Example: If 80 is 40% of a number, the original number is 200. Used to reverse-calculate GST or find original pre-tax prices.
Discount Calculator — Enter the original price and the discount percentage to instantly get the final sale price and the exact amount you save. Ideal for shopping sales, coupon codes, and e-commerce.
If you need to calculate percentages manually, here are the standard mathematical formulas utilized by our calculator engine:
To manually calculate 20% of a number, simply multiply the number by 0.20. For example, 20% of 500 = 500 × 0.20 = 100. Alternatively, divide the number by 5. For instant and error-free results, use the "% of Number" tab in our calculator above.
Percentage Change = ((New Value − Old Value) / Old Value) × 100. A positive result means a percentage increase (growth), while a negative result means a percentage decrease (reduction).
Discount % = ((Original Price − Sale Price) / Original Price) × 100. For example: If an item was originally ₹1000 and is now on sale for ₹750, the calculation is ((1000 - 750) / 1000) × 100 = 25% off.
If you paid ₹1180 including an 18% GST rate, you can find the original base price by dividing the total amount by (1 + GST rate). So, ₹1180 / 1.18 = ₹1000. Use our Reverse % tab — enter 1180 as the value and 118 (100 + 18) as the "is % of" field.
Percentage points measure the absolute difference between two percentages (e.g., moving from 5% to 7% is an increase of 2 percentage points). Percentage measures the relative change (moving from 5% to 7% represents a 40% increase). These are fundamentally different mathematical concepts!
Use the formula: (Marks Obtained ÷ Total Marks) × 100. Example: If you scored 450 out of 500, the calculation is (450 / 500) × 100 = 90%. You can instantly calculate this using the "X is % of Y" tab — just enter your marks as X and the total as Y.
Yes! WorldOfTools never saves, stores, or transmits the numbers you enter. All calculations are executed via local JavaScript in your browser, guaranteeing 100% data privacy for your sensitive financial or business figures.