Calculator
A simple online calculator for addition, subtraction, multiplication, and division, with percent (%) and sign toggle (±) keys. No installation needed — it runs right in your browser, and it fully supports keyboard input: digits, operators, Enter (=), Escape (clear), and Backspace, so you can calculate quickly without touching the mouse.
Examples
Use the % key for discounts
To find 20% off a ₩45,000 item, type 45000 × 20 %. Pressing % turns 20 into 0.2, and pressing = gives the discount amount of ₩9,000.
Calculate with the keyboard only
Enter expressions with the number keys and + - * /, then press Enter to see the result. Made a typo? Backspace deletes one digit at a time, and Escape clears everything (AC).
Use ± for negative numbers
When tracking expenses as negative numbers, type the amount and press ± to flip the sign. For example, 50000 ± + 120000 = gives −50,000 + 120,000 = 70,000.
FAQ
Can I type with my keyboard?
Yes. You can use the digits (0-9), the decimal point (.), the operators (+, -, *, /), and the percent key (%) directly. Enter works as =, Escape clears everything (AC), and Backspace deletes the last digit.
How does the % key work?
It divides the value currently on the display by 100. For example, typing 20 and pressing % gives 0.2. So '20% of 50,000' is entered as 50000 × 20 % =, which gives 10,000.
How is the order of operations handled?
Like a standard desk calculator, this calculator uses immediate execution: it evaluates in the order you type. For example, 2 + 3 × 4 gives (2 + 3) × 4 = 20. If you need multiplication and division to take precedence, enter that part first or use the scientific calculator.
Are decimal calculations like 0.1 + 0.2 accurate?
Computers store decimals in binary, so floating-point errors such as 0.1 + 0.2 showing as 0.30000000000000004 can occur. This calculator rounds results to 12 significant digits so such artifacts never appear.
Where can I do square roots or trigonometry?
This is a basic calculator focused on arithmetic. For square roots, exponents, trigonometric functions, and logarithms, use the scientific calculator page. For fraction arithmetic, use the fraction calculator.
Making the most of an online calculator
An online calculator needs no installation or sign-in — any browser works, so it's often faster than reaching for a physical calculator. On a PC you can type with the numeric keypad, and on a phone the large keypad buttons make input easy.
It handles everyday tasks like price comparisons, splitting bills, checking discounts, and unit-price calculations, and with the % key you can finish ratio calculations such as VAT or fees in just a few keystrokes.
How it differs from a scientific calculator
A basic calculator evaluates immediately in the order you type, which makes it ideal for quick arithmetic. A scientific calculator, by contrast, evaluates whole expressions with proper operator precedence and supports advanced functions like square roots, trigonometry, and logarithms.
This site offers calculators for specific needs: use the scientific calculator for full expressions, the fraction calculator for fraction arithmetic, the percentage calculator for discounts and rates of change, and the VAT calculator for value-added tax.
Related Calculators
Scientific Calculator
A free online scientific calculator with sine, cosine, tangent, logarithms (log and ln), exponents, and square roots. Type full expressions with parentheses, operator precedence, and DEG/RAD angle modes.
Fraction Calculator
Add, subtract, multiply, and divide fractions with automatic simplification. A free fraction calculator that shows the result as a simplified fraction, mixed number, and decimal.