About the Calculator
A no-nonsense everyday calculator. It does addition, subtraction, multiplication, division, percentages, and sign toggle — plus it keeps a running history of your previous calculations so you can scroll back and double-check your work. It's built for the kind of arithmetic you do at a kitchen table, in a classroom, or at a hardware-store checkout: tip calculations, splitting a bill, working out discount percentages, or chaining a quick sum without losing the previous result.
How to use it
- Tap or click number keys to enter values, then choose an operator.
- Press = to evaluate, or chain operators to keep calculating with the previous result.
- Use % to compute a percentage of the current value (handy for tips and discounts).
- Open the history panel to revisit a previous calculation and re-use the result.
Quick percentage shortcuts
| 10% of any value | value ÷ 10 |
| 15% tip on $40 | $6.00 |
| 20% tip on $40 | $8.00 |
| 25% off $80 | $60.00 |
| VAT 20% on £50 | £10.00 (total £60.00) |
| Sales tax 7% on $25 | $1.75 (total $26.75) |
Frequently asked questions
- Why does 0.1 + 0.2 not equal exactly 0.3?
- Computers store numbers in binary floating-point format, and some decimal fractions can't be represented exactly in binary — the same way 1/3 can't be written exactly in decimal. This is an IEEE 754 quirk shared by every calculator on every device. For everyday arithmetic the difference is far below anything you'd notice.
- Does the calculator obey order of operations?
- This is a basic four-function calculator, so it evaluates operators in the order you enter them rather than applying full PEMDAS. If you need parentheses and order-of-operations, type the inner expression first and use the running result.
- Can I see my previous answers?
- Yes — the history panel keeps a list of recent calculations. They persist in your browser between visits and can be cleared from Settings.
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