Free Online Calculator - Basic & Scientific Calculations

Calculate Anything Instantly

Our free online calculator handles all your math needs - from basic arithmetic to percentages and scientific calculations. No apps to download, no registration required. Just open and calculate on any device.

Online Calculator

Basic & scientific calculations, percentages, and more

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Calculator Features

Basic Math

Add, subtract, multiply, divide

Percentages

Calculate % of any number

Square Root

Find square roots instantly

Powers

Calculate exponents

Fractions

Divide and multiply

Negative

Work with negative numbers

How to Calculate Percentages

Learn how to calculate percentages with our easy formulas:

Find X% of a number:

(X ÷ 100) × number = result

What percentage is X of total:

(X ÷ total) × 100 = percentage

Or simply use our percentage calculator for instant results!

Common Calculations

  • Tip calculation - Calculate 15-20% tips at restaurants
  • Discounts - Find sale prices quickly
  • Interest rates - Calculate simple interest
  • Tax - Add or subtract tax amounts
  • Grade percentages - Calculate test scores
  • Growth rates - Measure percentage changes

Pro Tip

To calculate a 20% tip: multiply the bill by 0.20 (or divide by 5). For a 15% tip, multiply by 0.15. Our calculator makes this super fast!

Why Use Our Calculator?

  • Free forever - No subscription or payments
  • No downloads - Works in your browser
  • Mobile ready - Use on phone or tablet
  • Instant results - No loading time
  • Private - No data stored or tracked

Start Calculating Now

Open Calculator