Choose the right angle mode
sin, cos and tan take angles in the selected mode. asin, acos and atan return angles in that mode. For example, sin(30) is 0.5 in degrees; sin(pi/6) is approximately 0.5 in radians. The mode is recorded with every result. Changing it clears the displayed result until you calculate again.
Supported operations
Use +, -, *, / and ^ with parentheses. Powers associate right to left: 2^3^2 means 2^(3^2). Powers precede unary minus: -2^2 is -4, while (-2)^2 is 4. Factorial and percentage bind before powers. The percent operator always divides the preceding value by 100: 200*10% is 20; 200+10% is 200.1.
sqrt is the nonnegative square root; cbrt also accepts negative inputs. log is base 10, ln is natural log, exp(x) is e^x, and abs is absolute value. Factorial supports whole numbers 0–170. Double factorial (!!) is unsupported; use (3!)! if you intend repeated factorial. pi or π and e are constants. Scientific notation such as 1.5e-3 is supported. Function arguments require parentheses and multiplication must be explicit.
Editable expressions and useful history
Function buttons wrap selected text, or insert an opening function when nothing is selected. Close it with the ) key. Button edits, example/history selection and clearing history offer one Undo step that restores expression selection, angle mode, Ans, recent calculations and the previous result; ordinary typing uses your browser’s editing behavior and discards that button Undo. Ans uses the last successful result at full stored precision. Loading a history entry restores the earlier Ans value it used; calculate again to verify it. Clearing history also clears Ans and the displayed result, while preserving your expression.
Precision and limits
This is a real-number calculator using IEEE-754 double precision. The display rounds to 12 significant digits; exports also include the full stored number. Rounding, cancellation and underflow can affect results, and transcendental functions may vary slightly across browsers. Very small results can become zero. Use exact arithmetic tools for fractions or financial amounts.
Division by zero, invalid real domains, overflow and 0^0 are rejected. Tangent at, or extremely close to, a singularity is rejected. Trigonometric input magnitude is limited to 10¹²; large angles can still lose precision. Expressions are limited to 512 UTF-16 units, 256 tokens and 32 nested parser operations. No variables other than Ans, complex arithmetic, implicit multiplication or code execution. All processing and history stay in this browser. References: Number precision and Math functions.