Scientific Calculator With Expression Parser
Trig, logs, powers and roots with a real parser.
A scientific calculator should let you type the problem the way you would write it, not force you to compute it one button at a time. This one accepts full expressions with parentheses, powers, roots, trig, and logarithms, evaluated by a purpose-built parser in your browser, with no eval and no signup. Type an expression or tap the buttons, watch the degrees or radians indicator before trig work, and remember that the percent key converts a value rather than adding one.
Loading tool…
If the tool stays on this message, make sure JavaScript is enabled, then reload the page.
About Scientific Calculator
Sometimes you need more than a four-function calculator, logarithms, roots, and trig show up in homework, engineering estimates, and even finance. This one handles full expressions instead of making you compute button by button: write 3*(4+sqrt(16))/2 or sin(30)+log(100) and get the answer in one go. Everything runs on a hand-written expression parser in your browser, so there is no page reload, no signup, and no eval() executing arbitrary code, the formula you type is tokenized and evaluated by a purpose-built grammar.
The standard toolkit is all here: addition, subtraction, multiplication, division, powers, the percent key, parentheses, square root, sin, cos, tan, natural and base-10 logarithms, plus the constants pi and e. Trig defaults to degrees, with a DEG/RAD toggle for radian work. You can either tap the on-screen buttons or just type, implicit multiplication is understood, so 2pi, 3(4+1), and 2sqrt(9) all evaluate the way you'd write them on paper.
Watch for two common gotchas. Percent works as a value, not an operator: 50% becomes 0.5, so 200*10% is 20. And degrees versus radians is the single most common source of wrong trig answers. If sin(30) gives an unexpected result, check the DEG/RAD indicator before blaming the math.
Worked example: type 2*(3+sqrt(16)) and the parser works inside out, sqrt(16) is 4, 3+4 is 7, and 2 times 7 is 14. Type sin(30) in degree mode and the answer is 0.5.
How to use Scientific Calculator
- Type an expression or tap the buttons to build it.
- Use parentheses and functions like sin(30) or sqrt(16).
- Press = or Enter for the result.
- Check the DEG/RAD indicator before any trig calculation, since a mode mismatch is the most common cause of a wrong trig answer.
Why use this tool?
- Hand-rolled parser, no eval(), ever
- Degrees/radians toggle for trig
- Type expressions or tap the buttons
Tips for best results
- Type full expressions like 2*(3+sqrt(16)) instead of computing step by step, the parser handles nesting for you.
- Check the DEG/RAD indicator before any trig work; a mode mismatch is the most common wrong-answer cause.
- Use implicit multiplication (2pi, 3(4+1)) to enter formulas the way you'd write them on paper.
- Lean on parentheses to make order of operations explicit rather than trusting precedence from memory.
- Remember that 50% is 0.5, so 200*10% equals 20, the percent key converts a value, it doesn't add one.