Home / Free tools / Percentage Calculator

Free tool

Percentage Calculator

Four everyday percentage problems, one tool: X% of a number, X as a percent of Y, percentage change, and discount pricing.

Loading the calculator… (requires JavaScript; everything runs locally in your browser)

The four formulas, once and for all

X% of Y

Y × X ÷ 100. 15% of 2,400 = 360. Tips, commissions, tax estimates.

X is what % of Y?

X ÷ Y × 100. 45 of 60 = 75%. Test scores, targets achieved, market share.

Percentage change

(New − Old) ÷ Old × 100. 80 → 100 = +25%. Sales growth, price hikes. Note the asymmetry: 100 → 80 is −20%, not −25%.

Discount price

Price × (100 − d) ÷ 100. ₹2,499 at 30% off = ₹1,749.30. Sale pricing, negotiation math.

Frequently asked questions

How do I calculate a percentage of a number?

Multiply the number by the percentage and divide by 100. So 15% of 2,400 = 2,400 × 15 ÷ 100 = 360.

How is percentage change calculated?

(New − Old) ÷ Old × 100. Going from 80 to 100 is a 25% increase; going from 100 to 80 is a 20% decrease; the direction matters.

How do I work out a sale price?

Use the discount mode: price × (100 − discount%) ÷ 100. A ₹2,499 item at 30% off is ₹1,749.30.

Related free tools

Doing margin math all day?

Accounting software does it on every bill automatically. Busy, Tally and Vyapar at best rates.

See the software
🧰Free tools
💬 Get in touch