Basic Calculator

A simple online calculator supporting add, subtract, multiply, and divide, with decimal, sign toggle, percentage, and calculation history. Use the on-screen buttons or your keyboard.

History

No calculations yet

Tip: use your keyboard — number keys, + − * /, Enter (=), Backspace, Esc (AC).

Features

Add, subtract, multiply, divide

Decimal and negative numbers

Percent and sign toggle

Clear / backspace

Full keyboard support

Calculation history

How to Use

1. Click number and operator buttons to build an expression, then press = to evaluate.

2. Or use your keyboard: digits, + − × ÷, Enter (=), Backspace, Esc (clear).

3. +/- toggles the sign; % converts the current number to a percentage.

4. The History panel on the right keeps recent calculations — click any entry to recall the result.

About this tool

Sometimes a spreadsheet is too much and the phone is in another room. This calculator handles everyday arithmetic — addition, subtraction, multiplication, division, percentages and sign changes — with a history panel so you can glance back at what you worked out. It follows the way a pocket calculator works: each operation is applied as you press it, and results are rounded to 12 significant digits so floating-point noise such as 0.30000000000000004 does not show up. Very large or very small numbers switch to scientific notation. Everything responds to the keyboard, so you can type sums with the number pad, press Enter for equals, Backspace to fix a digit and Esc to clear.

Frequently Asked Questions

Does it follow operator precedence like 2 + 3 × 4 = 14?

No. Like a simple pocket calculator, it applies each operation in the order you enter it, so 2 + 3 × 4 gives 20. When precedence matters, work out the higher-priority part first: 3 × 4 = gives 12, then + 2 = gives 14.

How does the % key work?

Pressing % divides the current number by 100, so 15 % becomes 0.15. To take 15% of 80, enter 80 × 15 % = and the result is 12.

Why does 0.1 + 0.2 show 0.3 here but 0.30000000000000004 elsewhere?

Computers store decimals in binary, which cannot represent 0.1 exactly. The calculator rounds results to 12 significant digits before displaying them, which removes that noise for everyday sums without hiding real precision.

Which keyboard shortcuts are supported?

Digits and the decimal point enter numbers, + − * / choose operations, Enter or = evaluates, Backspace deletes the last digit and Esc clears everything. Shortcuts are ignored while you are typing in another input field.

Is my calculation history saved?

The history list lives only in the current page. It disappears when you close or reload the tab, and nothing is sent anywhere.