sin cos and tan calculator – Online Trigonometry Tool


sin cos and tan calculator

Your essential tool for trigonometry. Calculate sine, cosine, and tangent for any angle, with support for both degrees and radians.



Enter the angle value. The calculation updates in real-time.

Please enter a valid number.



Choose whether the angle is in degrees or radians.

Unit Circle Visualization

Interactive unit circle showing the angle and corresponding sin (vertical) and cos (horizontal) values.

What is a sin cos and tan calculator?

A sin cos and tan calculator is a digital tool designed to compute the fundamental trigonometric functions: sine (sin), cosine (cos), and tangent (tan). These functions are at the core of trigonometry, a branch of mathematics that studies the relationships between the angles and side lengths of triangles. This calculator accepts an angle as input, either in degrees or radians, and instantly provides the values for these three functions. It is invaluable for students, engineers, scientists, and anyone working with angles and geometric calculations.

The primary purpose is to simplify complex calculations that would otherwise require looking up values in trigonometric tables or performing complex series expansions. Whether you’re solving a problem for a right-angled triangle or analyzing wave functions, a sin cos and tan calculator provides immediate and accurate results, making it an essential utility.

The Formulas and Explanation

The definitions of sine, cosine, and tangent are based on the ratios of the sides of a right-angled triangle, often remembered by the mnemonic “SOH CAH TOA”.

  • Sine (sin): Opposite / Hypotenuse
  • Cosine (cos): Adjacent / Hypotenuse
  • Tangent (tan): Opposite / Adjacent

These ratios are also defined using the coordinates of a point on a unit circle (a circle with a radius of 1). For an angle θ, if a point (x, y) lies on the unit circle, the trigonometric functions are defined as:

  • sin(θ) = y
  • cos(θ) = x
  • tan(θ) = y / x

Variables Table

Variable Meaning Unit Typical Range
θ (theta) The input angle for the calculation. Degrees or Radians Any real number (e.g., 0 to 360° or 0 to 2π rad)
sin(θ) The sine of the angle, representing the ratio of the opposite side to the hypotenuse. Unitless Ratio -1 to 1
cos(θ) The cosine of the angle, representing the ratio of the adjacent side to the hypotenuse. Unitless Ratio -1 to 1
tan(θ) The tangent of the angle, representing the ratio of the opposite side to the adjacent side. Unitless Ratio -∞ to ∞

For more advanced calculations, check out our Triangle Solver.

Practical Examples

Example 1: Calculating for 30 Degrees

A classic example used in introductory trigonometry.

  • Input Angle: 30°
  • Units: Degrees
  • Results:
    • sin(30°) = 0.5
    • cos(30°) = 0.866
    • tan(30°) = 0.577

Example 2: Calculating for π/4 Radians

Using radians is common in higher-level mathematics and physics. π/4 radians is equivalent to 45 degrees.

  • Input Angle: 0.785398 (approx. π/4)
  • Units: Radians
  • Results:
    • sin(π/4) = 0.707
    • cos(π/4) = 0.707
    • tan(π/4) = 1.0

Need to convert between angle units? Use our Angle Converter tool.

How to Use This sin cos and tan calculator

Using this calculator is straightforward. Follow these simple steps for an accurate trigonometric evaluation.

  1. Enter the Angle: Type the numerical value of the angle you want to calculate into the “Angle (θ)” input field.
  2. Select the Unit: Choose whether your input angle is in “Degrees (°)” or “Radians (rad)” from the dropdown menu. This is a critical step as the results depend entirely on the unit.
  3. View the Results: The calculator automatically computes and displays the sine, cosine, and tangent values in the “Results” section. You will also see the angle converted to radians, which is the standard unit for JavaScript’s internal calculations.
  4. Analyze the Visualization: The unit circle chart dynamically updates to show a visual representation of the angle and the corresponding sin and cos values on the coordinate plane.
  5. Reset or Copy: Click the “Reset” button to clear the inputs and results, or click “Copy Results” to copy the calculated values to your clipboard for easy pasting elsewhere.

Key Factors That Affect the Calculation

The output of a sin cos and tan calculator is influenced by several key factors. Understanding them ensures you interpret the results correctly.

  • Input Angle (θ): This is the primary determinant. The values of sin, cos, and tan are periodic functions of the angle. For example, sin(0°) is 0, while sin(90°) is 1.
  • Unit of Measurement: Whether the angle is in degrees or radians is crucial. sin(90) in degrees is 1, but sin(90) in radians is approximately 0.89. Always double-check that you have selected the correct unit.
  • Function Quadrant: The sign (+ or -) of the result depends on the quadrant in which the angle’s terminal side lies on the unit circle. For example, cosine is positive in the 1st and 4th quadrants but negative in the 2nd and 3rd.
  • Calculator Precision: Digital calculators use approximations for irrational numbers. Our calculator uses high-precision floating-point arithmetic for maximum accuracy.
  • Tangent at 90° and 270°: The tangent function is undefined at 90° (π/2 rad) and 270° (3π/2 rad) because the cosine component is zero, leading to division by zero. Our calculator will indicate this.
  • Reciprocal Functions: While this calculator focuses on sin, cos, and tan, remember the reciprocal functions (cosecant, secant, cotangent) are directly related. An Inverse Trig Calculator can help find angles from ratios.

Frequently Asked Questions (FAQ)

1. What are sin, cos, and tan?
They are the three primary trigonometric functions that relate the angles of a right triangle to the ratios of its side lengths. “SOH CAH TOA” is a mnemonic to remember them: Sine = Opposite/Hypotenuse, Cosine = Adjacent/Hypotenuse, Tangent = Opposite/Adjacent.
2. What is the difference between degrees and radians?
They are two different units for measuring angles. A full circle is 360 degrees or 2π radians. Radians are the standard unit in many areas of mathematics and physics.
3. Why is tan(90°) undefined?
Because tan(θ) = sin(θ) / cos(θ). At 90°, cos(90°) is 0. Division by zero is mathematically undefined, so the tangent is also undefined at this angle and its multiples (like 270°).
4. Can I enter negative angles?
Yes. The calculator accepts negative angles. For example, sin(-30°) = -0.5, which is the same as sin(330°).
5. How does this calculator handle large angles?
The trigonometric functions are periodic. The calculator uses the modulo operator to find an equivalent angle within the primary range (0 to 360° or 0 to 2π rad) to ensure correct calculation for any large angle.
6. What is a unit circle?
A unit circle is a circle with a radius of 1 centered at the origin of a Cartesian plane. It provides a powerful way to visualize and define the trigonometric functions for all angles.
7. Where is trigonometry used in real life?
Trigonometry is used in many fields, including architecture, engineering, physics, astronomy, navigation (GPS), video game design, and signal processing.
8. How can I find an angle if I know the sin, cos, or tan value?
You would use the inverse trigonometric functions: arcsin, arccos, or arctan. Our Inverse Trig Calculator is designed for this purpose.

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