Calculator
Online calculator with standard, scientific (sin, cos, log, sqrt, n!) and programmer (BIN/OCT/HEX) modes — keyboard supported.
History
No operations yet
Click a result to reuse it.
Keyboard: 0–9 + − * / Enter Esc
This free online calculator is a standard calculator, a scientific calculator and a programmer calculator in one. It runs instantly in your browser — no app to install, no sign-up. Whether you need a quick simple calculator for everyday math, a scientific calculator with functions like sin, cos, log and n!, or an engineering calculator with BIN/OCT/HEX base conversion, every mode supports full keyboard input and a history panel.
Online Calculator: Standard, Scientific and Programmer Modes
This online calculator works in three modes — standard, scientific and programmer — entirely in your browser with no installation. The standard mode covers everyday four-operation math; the scientific mode adds trigonometric functions, logarithms, roots and factorials; and the programmer mode handles base conversion (BIN/OCT/HEX) and bitwise operations. Every mode supports both clicking and keyboard input, so you can use the calculator online exactly the way you would a physical one.
Standard Calculator and History
The standard mode handles the four basic operations (+, −, ×, ÷) plus percentages and sign change. The history panel lists the last 20 operations and keeps them in browser memory, so they remain after a page refresh. Click any past result to reuse it as the starting value of a new calculation. With keyboard support, you can use the digits 0-9, the + − * / operators, Enter (=), Escape (AC) and Backspace.
Scientific Calculator: Trigonometry, Logarithms and Factorials
The scientific mode adds the functions that the standard mode lacks:
- Trigonometry: sin, cos, tan — converted automatically to the unit chosen with the DEG/RAD selector.
- Logarithms: log (base 10) and ln (natural log).
- Powers and roots: x², xʸ and √ (square root).
- Constants: π (3.14159...) and e (2.71828...).
- Other: 1/x (reciprocal) and n! (factorial, up to 20!).
- Parentheses: ( ) for ordering operations.
Expressions follow standard operator precedence (PEMDAS/BODMAS): parentheses first, then powers, then multiplication/division, then addition/subtraction.
DEG and RAD: The Angle Unit Difference
Trigonometric functions give different results depending on the angle unit. In DEG (degrees) a full circle is 360°, while in RAD (radians) it is 2π. For example, sin(30) is 0.5 in degrees but about −0.988 in radians. Choose the right unit at the top of the scientific mode before calculating.
Programmer Calculator: BIN, OCT, HEX and Bitwise Operations
The programmer mode is built for software developers and computer-science students. It works in four base systems and converts the value automatically when you change the base:
| Base | System | Digits | Example (decimal 255) |
|---|---|---|---|
| BIN | Binary (base-2) | 0-1 | 11111111 |
| OCT | Octal (base-8) | 0-7 | 377 |
| DEC | Decimal (base-10) | 0-9 | 255 |
| HEX | Hexadecimal (base-16) | 0-9, A-F | FF |
Bitwise operations work directly on the binary representation: AND, OR, XOR, NOT, plus the << (left shift) and >> (right shift) operators. These are used in low-level programming, flag manipulation and performance optimization.
How to Calculate a Percentage
In standard mode the % key divides the current number by 100. For a discount, enter the price, press −, then the percentage and %, then =. For example: 500 − 20 % = gives 400 (20% of 500 is subtracted). For more advanced percentage math — percentage change, reverse percentage and more — use the dedicated percentage calculator.
How to Open and Use Calculator Modes
To open Calculator, simply load this page — it is ready to use the moment it appears, with no download. Here is how to use Calculator in any of its three modes:
- Choose a mode: Standard, Scientific or Programmer from the tabs at the top.
- Enter the numbers: click the buttons or type on your keyboard.
- Apply the operation: pick an operator or function and press = (or Enter).
- Use the result: copy it with the copy button, or click a history entry to reuse it.
Because it runs in the browser, this free online calculator works on any phone, tablet or computer without installing anything. See the FAQ section below for keyboard shortcuts and mode-specific details.
Frequently Asked Questions About the Calculator
Yes. The keyboard is fully supported in all three modes. Use 0-9 for digits, +, -, *, / for operators, Enter or = for equals, Escape to clear (AC), Backspace to delete the last character, and . for decimals. In scientific mode you can also type parentheses ( ).
At the top of scientific mode there is a DEG (degrees) / RAD (radians) selector. Trigonometric functions like sin, cos and tan are converted automatically. For example, sin(30) gives 0.5 in DEG mode and a different value in RAD mode.
BIN (base-2), OCT (base-8), DEC (base-10) and HEX (base-16) are supported. When you change the base the value is converted automatically. AND, OR, XOR, NOT bitwise operations and << >> bit shifting are also available.
In standard mode the last 20 operations are listed in the history panel and stored in browser memory. The history updates automatically after each calculation. Click a past result to use it as the starting value in a new calculation.
In standard mode the % key divides the number by 100. For a discount: enter 500, press -, then 20 % = → 20% of 500 (100) is subtracted, giving 400. For more advanced percentage math, use the Percentage Calculator.
The factorial is supported up to 20!. 20! = 2,432,902,008,176,640,000 ≈ 2.43 × 10^18. Values of 21 and above exceed JavaScript's safe-integer limit and return Error.
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