Scientific Calculator

A scientific calculator that reads a whole calculation the way it is written in maths, with brackets and the usual order of operations, and shows the answer as you type. It covers trigonometry in degrees or radians and the inverse functions, natural and base-10 logarithms, powers and roots, factorials, percentages, π and e. Press = or Enter to keep an answer in the history and reuse it as "ans" in the next calculation.

1. Type a calculation in the box, or tap the keys. You can type * and / as well as × and ÷, and ^ for powers.
2. Choose Degrees or Radians for sin, cos and tan and their inverses.
3. Read the answer under the box as you type. Press = or Enter to save it in the history; Escape clears the box.
4. Use "ans" for the last answer, and select any line in the history to put its calculation back in the box.

• Numbers are double-precision floating point, as on any handheld scientific calculator: about 15 to 16 significant digits. Answers are shown to 12, which hides rounding such as 0.1 + 0.2 = 0.30000000000000004. For exact work with fractions or very large whole numbers, use the Fraction or Factorial calculators.
• In degrees, angles whose sine, cosine or tangent is exactly 0, ±0.5 or ±1 give exactly that, and tan(90°) is refused as undefined rather than shown as a huge number. In radians, a result smaller than 10⁻¹⁵ from sin, cos or tan is shown as 0, since it is the rounding error in π.
• Factorial (!) takes whole numbers up to 170; 171! is beyond the largest number a double can hold.
• Only real numbers: the square root of a negative number, or a negative number to a fractional power, is refused. cbrt(x) and root(x, n) give odd roots of negative numbers.
• The calculator runs in this page on your device. What you type is not sent anywhere or saved; the history disappears when you leave the page.

Because a power binds more tightly than a minus sign, as in written maths: −2² means −(2²). Type (−2)^2 to square negative two.

Use the Degrees and Radians switch above the keys. It changes how sin, cos and tan read their angle, and what unit sin⁻¹, cos⁻¹ and tan⁻¹ give back. sin(30) is 0.5 in degrees and about −0.988 in radians.

log is the logarithm to base 10, so log(1000) = 3. ln is the natural logarithm, to base e ≈ 2.71828, so ln(e) = 1. For any other base, write log(x, base): log(8, 2) = 3.

% divides the number before it by 100, so 15% is 0.15 and 200 × 15% is 30. To add a percentage to a number, write it out: 200 × (1 + 15%) = 230.

Yes: the box takes typing and pasting. Write functions with brackets, as in sqrt(2) or sin(45). √2, 2π and 3(1 + 2) work without a × sign.