A clean, fast basic calculator for everyday arithmetic — right in your browser.
Sometimes you just need to punch in numbers. This standard calculator covers the everyday essentials — addition, subtraction, multiplication, division, percentages, sign toggle, and backspace — with a large display that shows both your running expression and the current value, so you can always see how you got to the number on screen.
Like every tool on QuickSum, it runs entirely in your browser: nothing you type is sent to a server, there's nothing to install, and it works the same on a phone, tablet, or desktop.
For anything beyond the basics, QuickSum has a purpose-built tool: percentages off a price belong in the discount & tip calculator, converting units in the unit converter, and money maths — loans, interest, investments — in the finance calculators. Each one shows its working, which a plain keypad never can.
No — like a traditional desk calculator, it evaluates each operation as you press the next operator, left to right. For 2 + 3 × 4 with algebraic precedence, compute 3 × 4 first, then add 2.
The buttons are click/tap driven in this version. On a desktop keyboard you may find your browser's built-in address-bar maths or our other calculators quicker for long expressions.
Results are accurate to about 15 significant digits — the standard for JavaScript floating-point arithmetic. Very large or very long-decimal calculations are rounded to 10 decimal places for display.