About the Basic Calculator
A fast, clean, everyday calculator right in your browser. Click the keys or type on your keyboard, hit Enter for the result — no app, no ads, no clutter.
This runs entirely in your browser, so it opens instantly and keeps working on a slow connection. Nothing you type is recorded anywhere.
How to use it
- Click the digits or type them on your keyboard.
- Use +, −, × and ÷ for the four operations, and Enter or = for the result.
- Press Esc or C to clear, and Backspace to delete the last digit.
Order of operations matters
This calculator follows standard mathematical precedence: multiplication and division are resolved before addition and subtraction. So 2 + 3 × 4 gives 14, not 20.
Many cheap pocket calculators do it the other way, evaluating strictly left to right. If a result ever surprises you, that difference is usually why.
A worked example
Working out a bill split: three items at 12.50, 8.75 and 21.30, plus 8% sales tax, divided between two people.
12.50 + 8.75 + 21.30 = 42.55. Multiply by 1.08 for tax: 45.95. Divide by 2: 22.98 each.
Doing it as one expression — 42.55 × 1.08 ÷ 2 — gives the same answer without writing anything down in between.
Common mistakes
- Typing 5 % 20 expecting a percentage. The percent key works on the running total, not as a standalone operator.
- Assuming a cleared display means a cleared memory. Clear the entry and the total separately if you are unsure.
- Rounding at every step instead of once at the end, which quietly accumulates error.
Questions people ask
Does it handle decimals and negative numbers?
Yes to both. Use the +/− key to flip a sign, and the decimal point as you would on paper.
Why does 0.1 + 0.2 sometimes show a long decimal?
That is binary floating-point arithmetic, and every computer does it — including spreadsheets. It only matters at the far right of the decimal, well beyond anything practical.
Is there a scientific version?
Yes — the Scientific Calculator adds trigonometry, logarithms, powers and roots.