🔢 Basic Calculator
Fast, clean online calculator with memory functions, percentage, square root, and full keyboard support.
Keyboard: numbers · + − * / · Enter = · Backspace · Escape = C · % · R = √
About This Calculator
This free online basic calculator handles everyday arithmetic — addition, subtraction, multiplication, and division — with a clean, distraction-free interface. It works on desktop and mobile, supports full keyboard input, and stores your last 20 calculations in a scrollable history panel.
Features
- Standard operations: Addition, subtraction, multiplication, division
- Functions: Percentage (%), square root (√), reciprocal (1/x), sign toggle (±)
- Memory: MC (clear), MR (recall), M+ (add), M− (subtract), MS (store)
- Keyboard support: Type numbers, operators, Enter for equals, Backspace to delete, Escape to clear
- History: Last 20 calculations — click any result to reuse it
- CE vs C: CE clears only the current entry; C resets the entire calculation
Keyboard Shortcuts
| Key | Action | Key | Action |
|---|---|---|---|
| 0–9 | Enter digit | Enter or = | Calculate result |
| + − * / | Operators | Backspace | Delete last digit |
| . | Decimal point | Escape | Clear all (C) |
| % | Percentage | R | Square root (√) |
| Delete | Clear entry (CE) | F9 | Toggle sign (±) |
How Percentage Works
The % button works contextually. After entering a number and an operator, pressing % converts the second number into a percentage of the first. For example: 200 + 15% calculates 200 + (200 × 0.15) = 230. This matches the behavior of most physical calculators and smartphone calculator apps.
Memory Functions Explained
- MS (Memory Store): Saves the current displayed value to memory
- MR (Memory Recall): Pastes the stored memory value into the display
- M+ (Memory Add): Adds the current value to whatever is in memory
- M− (Memory Subtract): Subtracts the current value from memory
- MC (Memory Clear): Erases the stored memory value (buttons dim when memory is empty)