Calculate what is X% of Y, what percent X is of Y, and the percentage increase or decrease between two numbers.
Anyone working out discounts, tips, tax, grades, or statistics quickly.
Pick the calculation
Choose the box that matches your question: percent of a number, one number as a percent of another, or the percentage change between two numbers.
Enter your numbers
Type the values into the fields. The result recalculates live as you type — no submit button.
Read the result
The answer appears in bold; percentage decreases show in red and increases in green so you can’t misread the direction.
Percentages are everywhere in daily life — a discount in a sale, a tip, a test score, a tax rate, a change in price or followers — but they trip people up because the word "percent" hides three different questions. "What is 20% of 80?", "15 is what percent of 60?", and "what is the change from 80 to 100?" each need a different formula, and grabbing the wrong one quietly gives the wrong answer. This calculator separates those three questions into their own boxes, so you pick the one that matches what you are actually asking and just type the numbers. Results update instantly as you type, with increases and decreases colour-coded so a rise and a fall are impossible to confuse. Everything is calculated in your browser, so nothing is uploaded, and there is no sign-up — it is built to give you a quick, correct answer without you having to remember which formula goes where.
Shopping & discounts
See how much a "30% off" actually saves, or work out the discount percentage from an original and sale price.
Grades & scores
Turn marks into a percentage — for example, 47 out of 60 — to check against a pass mark or grade boundary.
Finance & business
Calculate percentage growth or decline between two figures such as revenue, costs, or budget.
Tax, tips & VAT
Add or work back a percentage for sales tax, VAT, service charges, or commission.
Stats & reporting
Express one number as a share of a total, or report the change between two periods.
Multiply: X ÷ 100 × Y. The first box does this for you — e.g. 20% of 80 is 16.
Divide and multiply by 100: part ÷ whole × 100. So 15 out of 60 is 25%.
Percentage change = (new − old) ÷ |old| × 100. The third box handles it automatically.
Yes. A drop from 100 to 80 shows as −20%, and a rise from 80 to 100 shows as +25%.
Going from 10% to 12% is a 2 percentage-point rise but a 20% increase. This tool reports the percentage change of the values you enter.
Yes — use the "percent of" and "change" boxes together, or the dedicated Discount Calculator for sale-price problems.
No. All the maths runs in your browser; nothing you type is uploaded.
Yes — run unlimited percentage calculations for free, with no sign-up.