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Math

Scientific Calculator

Free online scientific calculator with trigonometry in degrees or radians, powers, roots, logarithms, factorials, parentheses and a history of your last 10 results.

Free · no sign-up Runs in your browser
Type an expression or use the keys, then press Enter or =. Escape clears.
Angle unit

History

No calculations yet. The last 10 results appear here; select one to reuse it.

    How to use the calculator

    Click the keys or type straight into the expression box, then press = or Enter. Escape clears the box. You can type * and / instead of × and ÷, and sqrt instead of √.

    Use the DEG / RAD switch to choose whether angles are in degrees (the default) or radians. It affects sin, cos and tan and the results of asin, acos and atan.

    After a result is shown, pressing an operator key continues the calculation with that result, while pressing a number or function key starts a new one. The last 10 calculations are listed under History; select one to bring its result back. The history is kept only while the page is open.

    Order of operations

    The calculator follows the standard order, from first to last:

    1. Parentheses
    2. Factorial !, percent % and squares ²
    3. Powers ^, worked from right to left, so 2^3^2 = 2^9 = 512
    4. A leading minus sign, so −2^2 = −(2^2) = −4
    5. Multiplication and division, from left to right
    6. Addition and subtraction, from left to right

    Example: 3 + 4 × 2^2 = 3 + 4 × 4 = 3 + 16 = 19.

    Writing expressions

    • A number directly before a parenthesis, a constant or a function is multiplied: 2π = 6.28318530718, 3(4+5) = 27 and 2sin(30) = 1. Two plain numbers side by side, such as 2 3, are treated as a mistake.
    • Implied multiplication has the same priority as ×, so 1/2π means (1/2) × π. Add parentheses when you mean 1/(2π).
    • % divides by 100: 50% = 0.5 and 200 × 15% = 30.
    • log is the base-10 logarithm and ln is the natural logarithm.
    • For very large or small numbers use a capital E: 1.5E3 = 1500. A lowercase e is Euler's number, 2.718…
    • A missing closing parenthesis at the end is added for you, so sin(30 gives 0.5.

    Accuracy

    Results are rounded to 12 significant digits. This hides the tiny rounding errors that all computers make with decimal numbers, so 0.1 + 0.2 shows 0.3 and sin(180°) shows 0. Very large or very small results are shown in E notation.

    Good to know

    • Some operations have no real answer and show a clear message instead: dividing by zero, the square root or logarithm of a negative number, tan(90°), and asin or acos of a value outside −1 to 1.
    • Factorials work for whole numbers from 0 to 170. 171! is larger than the biggest number the calculator can hold.
    • A negative number cannot be raised to a fractional power here, so (−8)^(1/3) shows an error.

    Frequently asked questions

    Why is −2^2 equal to −4 and not 4?

    Powers are worked out before the leading minus sign, as in standard mathematical notation. So −2^2 means −(2^2) = −4. If you want the square of −2, write (−2)^2, which is 4.

    Should I use degrees or radians?

    Use degrees for everyday angles, such as in geometry or building work, where a full turn is 360°. Use radians in calculus, physics and most programming, where a full turn is 2π. The DEG/RAD switch above the expression box changes the mode, and degrees is the default.

    Why does tan(90) show an error?

    In degrees, tan(90°) is sin(90°) divided by cos(90°), and cos(90°) is zero. Division by zero has no value, so the tangent is undefined there. The same applies to 270°, −90° and so on, or to π/2 in radian mode.

    What is the difference between log and ln?

    log is the base-10 logarithm: log(1000) = 3 because 10³ = 1000. ln is the natural logarithm with base e ≈ 2.718: ln(e) = 1. Both are only defined for numbers greater than zero.

    Is my calculation history saved?

    The history keeps your last 10 calculations only while the page is open. It is not stored on your device or sent anywhere, and it disappears when you close or reload the page.