Scientific Calculator Online

Scientific calculator: functions, syntax, and gotchas

A scientific calculator goes beyond the four basic operations to handle trigonometry, logarithms, exponents, roots, and factorials. This one accepts typed expressions as well as an on-screen keypad, so you can enter a whole formula at once. Below is a reference for the supported functions, the syntax it expects, and the quirks worth knowing before you trust a result.

Supported functions and constants

• Trigonometry: sin, cos, tan and their inverses asin, acos, atan (arguments in radians).
• Logarithms: log (base 10), log2 (base 2), log10, and ln (natural, base e).
• Roots and powers: sqrt, cbrt, exp, and the ^ operator for any exponent.
• Rounding and sign: abs, floor, ceil, round, sign.
• Constants: π (3.14159…) and e (2.71828…), available as keys or by typing pi and e.
• Factorial: n! for non-negative integers.

Writing expressions correctly

The calculator reads a normal infix expression, so you can type something like 2*sin(π/4) + sqrt(16) in one go. A few rules keep results correct:

• Always close every parenthesis you open; unbalanced brackets cause an error.
• Multiplication must be explicit: write 2*π, not 2π.
• Use ^ for powers (3^4 = 81) and the √ key for roots (sqrt(2) ≈ 1.414).

Radians vs degrees

This is the single most common source of wrong trig answers. The functions operate in radians, where a full circle is 2π. If your angle is in degrees, convert it first by multiplying by π ÷ 180. So the sine of a 45-degree angle is sin(45 * π / 180), which returns about 0.707, not sin(45), which interprets 45 as radians.

Order of operations

The evaluator follows standard precedence: parentheses, then exponents, then multiplication and division, then addition and subtraction. 2 + 3 * 4is 14, not 20. When in doubt, add parentheses — they never change a correct expression and they prevent surprises.

Floating-point precision

Like virtually all digital calculators, this tool uses binary floating-point numbers. Most results are exact to many digits, but a few decimals (such as 0.1 + 0.2) show a tiny trailing error because they cannot be represented exactly in binary. For everyday math this is invisible; for precise work, round the answer to the number of decimal places you actually need.

Related tools

• Percentage Calculator— percent of, ratios, and percent change.
• Length Converter— convert between metric and imperial units.
• Compound Interest Calculator— model exponential growth over time.