Basic Calculator
Everyday arithmetic with keyboard and keypad input plus live results.
Type directly with your keyboard (numpad works too) and press Enter, or tap the buttons. Supported functions: sin cos tan ln log sqrt abs exp · constants: π e.
About this calculator
A fast four-function calculator with percentage support that accepts typed expressions like 25*4+10 as well as button taps. Results preview live as you type — press Enter to lock a value in.
The engine is a proper tokenizer-and-shunting-yard parser, not JavaScript eval(), so malformed expressions fail safely with helpful messages.
Frequently Asked Questions
Does the numpad on my keyboard work?
Yes — digits, operators and Enter all register, whether from the top row or the numeric keypad.
How does % behave?
It acts as modulo/remainder in expressions (17 % 5 = 2), matching scientific convention.