Operator precedence
Expressions follow standard precedence: exponentiation first, then multiplication and division, then addition and subtraction. So 2 + 3 × 4 is 14, not 20 — brackets are needed to force the other reading.
Exponentiation is right-associative, meaning 2^3^2 evaluates as 2^(3^2) = 512, not (2^3)^2 = 64. This matches mathematical convention and most scientific calculators.
Trigonometry works in radians
sin, cos and tan take radians, not degrees. To use degrees, convert first: sin(30 × pi / 180). A full circle is 2×pi radians, and pi is available as a constant.
log is base 10 and ln is the natural logarithm, following the convention used in most engineering contexts.
Working in degrees
The trigonometric functions here take radians, which is the mathematical standard. To work in degrees, multiply by pi and divide by 180 first: the sine of 30 degrees is written sin(30 * pi / 180), which returns 0.5.
Going the other way, radians to degrees is multiply by 180 and divide by pi. A right angle is pi/2 radians, a straight line is pi, and a full turn is 2*pi.
Implicit multiplication and common mistakes
Writing 2(3+4) is understood as 2*(3+4), and 2pi works as expected. Where expressions get ambiguous is division: 1/2x is parsed as (1/2)*x, not 1/(2x). When in doubt, add brackets — they cost nothing and remove the ambiguity entirely.
Exponentiation binds tighter than unary minus, so -2^2 evaluates to -4, following standard mathematical convention. Write (-2)^2 if you want 4.
Frequently asked questions
Why does sqrt(-1) give an error? +
The calculator works over real numbers only, and the square root of a negative number is imaginary. Any expression producing a non-real or infinite result reports an error rather than a misleading value.
How do I calculate a percentage here? +
Percentages are just division by 100. For 15% of 240, enter 240 * 15 / 100. The dedicated percentage calculator handles the other common variations.
What is the difference between log and ln? +
log is base 10 and ln is base e, the natural logarithm. log2 is also available for base 2.