Percentage Calculator

Handle common percentage math for discounts, score changes, salary growth, markups, taxes and tips without doing the arithmetic manually.

Discounts Percent change School and finance

Quick examples

What is X% of Y?

X is what % of Y?

Percentage increase or decrease

Common uses

Related tools: Currency Converter, Profit & Loss Calculator, SIP Calculator.

Frequently Asked Questions

How do I calculate a discount percentage?

Use the "Percentage increase or decrease" section. Enter original price as "Original value" and sale price as "New value" to get the discount %.

How do I reverse a percentage?

If something increased by 20%, divide by 1.20. If it decreased by 20%, divide by 0.80. The calculator shows the change value automatically.

What is the formula for percentage change?

% Change = (New Value − Old Value) ÷ Old Value × 100. Positive = increase, Negative = decrease.

Can I calculate tax and tip?

Yes. Enter the tax/tip percentage and the base amount in the "What is X% of Y" section to get the total.

✅ Do's and ❌ Don'ts

✅ Do's

  • ✅ Do double-check that you're entering the base value in the right field.
  • ✅ Do use decimal precision for financial calculations (e.g., 12.5%).
  • ✅ Do round appropriately — for currency, round to 2 decimal places.

❌ Don'ts

  • ❌ Don't confuse "X% of Y" with "X is what % of Y" — they are different calculations.
  • ❌ Don't use percentages directly in markup — a 50% markup is not the same as a 50% margin.
  • ❌ Don't divide by zero — the calculator will flag this automatically.
📐 How Percentage Works

X% of Y → (X ÷ 100) × Y

X is what % of Y → (X ÷ Y) × 100

% Change → (New − Old) ÷ Old × 100

Example: Shopping Discount

A ₹2,500 jacket is 30% off → Discount = 2500 × 0.30 = ₹750 → Sale price = ₹2,500 − ₹750 = ₹1,750

Also try: Profit & Loss · Currency Converter · GST Calculator

Frequently Asked Questions

Is this tool free to use?

Yes. All UpTools calculators are completely free, with no sign-ups required.

Is my data private?

Yes. All calculations run locally in your browser. Nothing is uploaded to any server.

Does it work on mobile?

Yes. All tools are mobile-responsive and work on any device — phone, tablet, or desktop.

Can I use this offline?

Most tools work offline after the initial page load. No internet needed for calculations.

📐 How This Tool Works

This tool computes results entirely in your browser using JavaScript. No data is sent to any server, ensuring your privacy.

Results update instantly as you type — no waiting for server responses.

Also try: Calculator · Converter · Generator