A two-line scientific calculator for everyday trig, logs, powers, roots, and factorials. Tap the keypad or type an expression; equals stores a short history. Angles default to degrees.
Entering an expression correctly
Use parentheses to make grouping explicit, especially inside functions and
fractions. For example, (2 + 3) / (4 + 1) equals 1, while 2 + 3 / 4 + 1
follows operator precedence and gives a different result. Powers are evaluated
right to left, so 2^3^2 means 2^(3^2).
The parser accepts implicit multiplication in inputs such as 2pi and
2(3 + 4), though an explicit * can make a long expression easier to audit.
Use the editable display to correct one character or function without clearing
the full calculation.
Degrees and radians
DEG and RAD affect trigonometric functions, not ordinary arithmetic. One full
rotation is 360 degrees or 2π radians. Use degrees for an angle written with a
degree symbol and radians when a formula contains π or when working in most
calculus settings. Thus sin(30) is 0.5 in DEG mode, while sin(pi/6) is 0.5 in
RAD mode.
Inverse trigonometric functions return an angle in the selected mode. If an answer looks unexpectedly small or large, check the mode before changing the expression.
Domains and error messages
Some expressions have no real-number result. The square root of a negative
number, division by zero, ln(0), and factorial of a negative or non-integer
value produce an error. Tangent is undefined at odd multiples of 90° (or
π/2 radians), although finite-precision arithmetic can display a very large
nearby value.
For a visual check of a formula across many x-values, use the Graphing Calculator. The Exponent Calculator shows step-by-step power and root relationships, while the Fraction Calculator preserves exact rational forms instead of only decimal approximations.
Common keys
| Key | Meaning |
|---|---|
| sin, cos, tan | Trig in the current DEG/RAD mode |
| ln, log | Natural log and log base 10 |
| x², xʸ, √x | Square, power, square root |
| 1/x, n! | Reciprocal and factorial |
| π, e | Pi and Euler's number |
| AC, Back | Clear all / delete last |
Examples
2 + 3
5. The default expression on this page.
sin(3) in degrees
3° in radians is 3π/180. sin(3°) ≈ 0.0523359562. Switch to RAD and the same input is sin(3) ≈ 0.1411200081.
5 factorial
5! = 5 × 4 × 3 × 2 × 1 = 120.
Formula
Trigonometric functions convert degrees to radians when DEG is selected:
sin_rad(x) = sin(x × π ÷ 180) when mode is DEG
sin_rad(x) = sin(x) when mode is RAD
Exponentiation is right-associative (2^3^2 = 512). Factorial is postfix
(5! = 120). Constants:
π ≈ 3.1415926536
e ≈ 2.7182818285
After equals, a digit starts a new expression, while an operator continues from the result — so 2+3 = 5, then ×4 = 20.
Precision and rounding
Constants and results are stored as JavaScript double-precision numbers. The display rounds long results for readability, so the last shown digit should not be treated as laboratory-grade measurement precision. For chained work, continue from the stored result rather than manually retyping a heavily rounded value.
Sources
- NIST Digital Library of Mathematical Functions: Elementary Functions
- NIST Digital Library of Mathematical Functions: Computation
Evaluation limits
The parser follows the displayed precedence and angle mode; implicit conventions can differ among calculators, especially around unary minus, powers, and percent notation. Trigonometric inputs use the selected degree or radian mode. Results use finite floating-point arithmetic, so very large values, cancellation, and transcendental functions can show rounding error.