Everyday Math
Scientific Calculator
What Is a Scientific Calculator?
A scientific calculator performs complex mathematical operations beyond basic arithmetic — including trigonometry, logarithms, exponents, factorials, roots, and more. Our free online scientific calculator works instantly in your browser with no download or sign-up required.
Trigonometric Functions (sin, cos, tan)
- sin(θ) — ratio of opposite side to hypotenuse.
- cos(θ) — ratio of adjacent side to hypotenuse.
- tan(θ) — ratio of opposite to adjacent (sin ÷ cos).
Always select Degrees or Radians mode before calculating — this is the most common source of errors.
Common Angle Values
| Angle | sin | cos | tan |
|---|---|---|---|
| 0° | 0 | 1 | 0 |
| 30° | 0.5 | 0.866 | 0.577 |
| 45° | 0.707 | 0.707 | 1 |
| 60° | 0.866 | 0.5 | 1.732 |
| 90° | 1 | 0 | undefined |
Logarithms
- log(x) — Common log (base 10). Example: log(1000) = 3.
- ln(x) — Natural log (base e ≈ 2.71828). Inverse of eˣ. Used in finance, calculus, and science.
Exponents and Roots
- x² — squares the number. xʸ — raises x to power y. √x — square root. eˣ — inverse of ln(x).
Order of Operations (PEMDAS / BODMAS)
- Parentheses / Brackets
- Exponents / Orders
- Multiplication and Division (left to right)
- Addition and Subtraction (left to right)
Related Tools
Percentage Calculator — instant percentage and proportion calculations. Unit Converter — convert between any scientific units.
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How to Use
- 1Select DEG or RAD modeChoose Degrees for everyday angles (e.g., 90°) or Radians for mathematical/scientific calculations (π radians = 180°).
- 2Use buttons or keyboardClick buttons to build your expression, or type directly on your keyboard. All standard keys are supported.
- 3Press = or EnterHit the equals button or press Enter to evaluate. The result appears in the display.
Frequently Asked Questions
What is the difference between DEG and RAD mode?
DEG (degrees) and RAD (radians) are two ways to measure angles. 360° = 2π radians. For everyday use, degrees are more intuitive. For calculus and physics, radians are standard. Always check your mode before using trig functions.
How do I calculate sin(30°)?
Make sure the calculator is in DEG mode, type 30, then press sin. The result is 0.5. In RAD mode, you would enter π/6 ≈ 0.5236 first.
What is log vs ln?
log (or log₁₀) is the logarithm base 10. ln is the natural logarithm base e (≈2.718). log(100) = 2 because 10² = 100. ln(e) = 1. Use log for pH, decibels, and magnitude calculations; use ln for compound interest and exponential growth formulas.
How do I use the memory buttons?
MC = clear memory. MR = recall stored value. M+ = add current display to memory. MS = store current display to memory. Memory is useful when you need to use an intermediate result in a later calculation.