Calculator — free online basic calculator

How it works

The calculator evaluates what you type as a single expression, following the standard order of operations: multiplication and division are carried out before addition and subtraction, each from left to right. So 2 + 3 × 4 is 2 + 12 = 14, because the multiplication happens first — not 20.

The keypad also gives you:

• Memory — M+ adds the current value to memory, M− subtracts it, MR recalls the stored number, and MC clears it. A small M shows while a value is stored.
• AC clears everything; ⌫ deletes the last entry; ± negates the current expression; and % turns a number into a fraction, so 200 × 15% is 200 × 0.15 = 30.

Worked example

To work out 15 + 45 ÷ 9, the calculator divides first — 45 ÷ 9 = 5 — then adds 15 + 5. Entering 15 + 45 ÷ 9 = gives 20. Because division is done before addition, you do not need to enter the steps separately.

Frequently asked questions

How does this calculator handle order of operations?

It follows the standard order of operations (PEMDAS / BODMAS): multiplication and division are done before addition and subtraction, each from left to right. Multiplication is not "stronger" than division, nor addition than subtraction — each pair shares one precedence level.

Why does 2 + 3 × 4 equal 14 and not 20?

Because multiplication is done before addition: `3 × 4 = 12` first, then `2 + 12 = 14`. Reading strictly left to right would give 20, but that ignores the order of operations every calculator and maths convention follows.

What does the percent (%) key do?

It converts the preceding number to a fraction by dividing it by 100. So `50%` becomes `0.5`, and `200 × 15%` evaluates as `200 × 0.15 = 30`.

How do the memory keys work?

Memory holds one number. **M+** adds the current value to it, **M−** subtracts the current value, **MR** recalls the stored number into your expression, and **MC** resets memory to zero. An **M** indicator appears while a value is stored.

What is the difference between AC and the backspace key?

**AC** (all clear) erases the whole expression and any result for a blank slate. The backspace key **⌫** deletes only the last character you entered, so you can fix a typo without starting over.

How are very large or very small results shown?

Results are grouped with separators and rounded to about 12 significant digits, which hides tiny rounding artifacts (so `0.1 + 0.2` shows `0.3`). A result that is too large or too small to show in full switches to scientific notation, such as `1E15`.