Scientific Calculator - sin, cos, log, sqrt & More

How to use this tool

1. Select DEG or RAD mode for trigonometric functions.
2. Click keypad buttons or type directly into the expression field.
3. Press = or Enter to calculate.
4. Click any history entry to reuse a previous result.

Scientific calculator functions

This calculator evaluates full mathematical expressions, not just one operation at a time. Type sin(45) + sqrt(16) / 2 and press Enter to get the result instantly.

Supported functions

• Trigonometry: sin, cos, tan (inverse: asin, acos, atan)
• Logarithms: log (base 10), ln (natural logarithm)
• Exponential: exp(x) = eˣ
• Roots & powers: sqrt(x), x^y
• Rounding: ceil, floor, round, abs
• Factorial: factorial(n) for non-negative integers up to 170
• Modulo: a % b returns the remainder after dividing a by b

The % key means modulo (remainder), not a percentage. For example, 10 % 3 returns 1 because 10 divided by 3 leaves a remainder of 1.

Constants

Use pi (or π) for π ≈ 3.14159 and e for Euler's number ≈ 2.71828. Implicit multiplication works: 2pi = 2π.

Expression tips

• Use ^ for exponents: 2^8 = 256
• Chain functions: sqrt(sin(30)^2 + cos(30)^2) = 1
• Implicit multiplication: 2(3+4) = 14
• Unary minus: -sin(45) negates the result

Degrees vs radians

Toggle between DEG and RAD to control how angles are interpreted. In DEG mode, sin(90) = 1. In RAD mode, sin(pi/2) = 1.

Order of operations

The expression parser follows standard PEMDAS/BODMAS precedence: Parentheses, Exponents, Multiplication and Division (left to right), Addition and Subtraction (left to right). Important edge cases to know:

• Implicit multiplication vs. division: 6 / 2(3) is evaluated as (6 / 2) × 3 = 9, not 6 / (2 × 3) = 1. Use parentheses when the intent is ambiguous.
• Unary minus with exponents: -2^2 is evaluated as -(2^2) = -4 because exponentiation binds tighter than unary negation. To get (-2)² = 4, write (-2)^2.

Precision and floating-point

JavaScript (and this calculator) uses 64-bit IEEE 754 double-precision floating-point arithmetic, which provides about 15–17 significant decimal digits of precision. This leads to a well-known quirk: 0.1 + 0.2 evaluates to 0.30000000000000004 rather than exactly 0.3. The calculator rounds results to a sensible number of significant digits for display, so most everyday calculations show clean results - but extremely precise comparisons (e.g., testing whether two results are exactly equal) may reveal floating-point artifacts.