Free Online Basic Calculator
Instantly perform addition, subtraction, multiplication, division, and percentage calculations. A fast, accurate, and mobile-friendly math tool for everyday use.
Calculate Your Numbers
Use the keypad below or your physical keyboard to perform quick, reliable mathematical calculations.
Calculator Keypad
Click the buttons or use your keyboard to calculate
History & Math Tips
Your recent calculations and quick references
Common Math Equivalents
Standard conversions between fractions, decimals, and percentages to help you quickly verify your calculations.
| Fraction | Decimal | Percentage | Common Use |
|---|---|---|---|
| 1/2 | 0.5 | 50% | Half |
| 1/3 | 0.333… | 33.33% | Third |
| 1/4 | 0.25 | 25% | Quarter |
| 1/5 | 0.2 | 20% | Fifth |
| 3/4 | 0.75 | 75% | Three Quarters |
| 1/8 | 0.125 | 12.5% | Eighth |
| 1/10 | 0.1 | 10% | Tenth |
Basic Calculator FAQ
Everything you need to know about using this tool and understanding fundamental math concepts.
PEMDAS stands for Parentheses, Exponents, Multiplication and Division (from left to right), and Addition and Subtraction (from left to right). This is the standard rule used to solve mathematical expressions correctly and consistently.
To find a percentage of a number, multiply the number by the percentage divided by 100. For example, to find 20% of 50, calculate 50 × (20 / 100) = 50 × 0.20 = 10.
A basic calculator handles fundamental arithmetic operations like addition, subtraction, multiplication, and division. A scientific calculator includes advanced functions such as trigonometry (sin, cos, tan), logarithms, exponents, and complex equation solving.
To convert a fraction to a decimal, simply divide the numerator (top number) by the denominator (bottom number). For example, 3/4 is calculated as 3 ÷ 4 = 0.75.