How to use the Basic Calculator
- Type an expression directly into the display, or tap the keypad.
- Use brackets to group any part that must be evaluated first.
- Press = to evaluate, or C to clear the whole entry.
- Use ⌫ to remove the last character if you mistype a digit.
How the calculation works
The calculator parses your expression rather than applying operations one keypress at a time. That difference matters: a chained pocket calculator computes 2 + 3 × 4 as 20, because it acts on each key as it arrives, while an expression parser returns 14, honouring the standard order of operations. Multiplication and division bind more tightly than addition and subtraction, and anything inside brackets is resolved first.
Evaluation uses the shunting-yard algorithm — the expression is converted from the infix form you type into postfix order, then evaluated on a small stack. Numbers are handled in IEEE 754 double precision, the same arithmetic every browser and spreadsheet uses, so results carry roughly 15–17 significant decimal digits. That precision is ample for money, measurements and schoolwork, but it is binary floating point, so a value like 0.1 + 0.2 has a tiny representation error that only appears at the far right of a long decimal.
Order of operations: brackets → exponents → multiplication and division (left to right) → addition and subtraction (left to right)Source: Standard mathematical order of operations (BODMAS/PEMDAS); shunting-yard parsing as described by Edsger Dijkstra.
Worked example
Splitting a $184.50 restaurant bill four ways after adding an 18% tip.
- Type 184.50 * 1.18 to add the tip → 217.71.
- Wrap it and divide: (184.50 * 1.18) / 4.
- Press = to evaluate.
$54.43 per person, in one expression rather than three separate steps.
Frequently asked questions
Does it follow order of operations?+
Yes. Brackets bind first, then multiplication and division, then addition and subtraction, evaluated left to right within each level.
Can I type instead of tapping?+
Yes — the display is an editable field, so you can paste or type a full expression including brackets.
Why does a long decimal end in stray digits?+
Binary floating point cannot represent some decimal fractions exactly. Round the result to the precision your task actually needs.
Is my input sent anywhere?+
No. Everything is evaluated in your browser; nothing is transmitted or stored.
Last reviewed September 1, 2026. We review this page whenever the underlying formula, tax year, published rate or standard changes.