Scientific Calculator

This free online scientific calculator works like a TI or Casio handheld, right in your browser. It handles everything a basic calculator can't: trigonometry, logarithms, exponents, roots, factorials, and constants like π and e — with a memory bank and a clear running display of your expression.

How it's calculated

The calculator evaluates your expression using the standard order of operations (PEMDAS): parentheses first, then exponents, then multiplication and division left to right, then addition and subtraction.

2 + 3 × 4^2  =  2 + 3 × 16  =  2 + 48  =  50
sin(30°)     =  0.5          (degree mode)
log(1000)    =  3            ln(e) = 1
5!           =  5 × 4 × 3 × 2 × 1  =  120

The keypad, briefly:

• Trig keys (sin, cos, tan) respect the DEG/RAD toggle. In degree mode, sin(30) = 0.5; in radian mode, sin(30) ≈ −0.988 because 30 radians is about 4.77 full turns around the circle. Inverse functions (sin⁻¹, cos⁻¹, tan⁻¹) return angles in the current mode.
• Logarithms: log is base 10, ln is base e (natural log). For any other base, use the change-of-base identity: log₂(x) = ln(x) ÷ ln(2).
• Powers and roots: x² squares, x^y raises to any power, √ takes the square root. Negative inputs to √ return an error rather than a complex number.
• Factorial (n!) multiplies all whole numbers from n down to 1. It is defined here for non-negative integers; 170! is the largest value double-precision math can hold (~7.26 × 10³⁰⁶), so this calculator rejects anything above 170 with an error.
• Memory keys: M+ adds the displayed value to memory, M− subtracts it, MR recalls it, and MC clears it — handy for multi-step problems.

Assumptions and limitations: all arithmetic uses IEEE-754 double-precision floating point, which is accurate to roughly 15–17 significant digits. Tiny rounding artifacts (like 0.1 + 0.2 showing 0.30000000000000004 on naive calculators) are cleaned up in the display, but extremely large or small intermediate values can still lose precision. For symbolic math (exact fractions, algebra), use a CAS instead.