Secant Calculator for Degrees or Radians

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On this page is a secant calculator. Input an angle's measurement, choose your units, and run the calculator to see the secant.

Secant Calculator for Angles or Radians

Using the Secant Calculator

To use the tool to find the secant, enter the measurement of the angle in either degrees or radians, choose your units, and compute.

  • Angle - measurement of the angle, in degrees or radians
  • Degrees or Radians? - choose your units in the menu

Once happy, click the "Compute Secant" button.

  • Secant - the secant, or ratio of the hypotenuse over the adjacent side's measurement

What is the secant?

For a given angle in a right triangle, secant is the ratio of the longest side (the hypotenuse) to the adjacent side. Secant is the reciprocal of the cosine; cosine is the ratio of the adjacent side's length to the hypotenuse.

Right triangle to illustrate trigonometry functions
Right Triangle Diagram (CC By-SA 3.0 Wikimedia)

Trigonometric functions such as the secant are also used to find the ratio between sides of a unit circle (a circle with radius 1).

Unit Circle to illustrate trigonometry.
Unit circle diagram (CC By-SA 3.0 Wikimedia)

Secant as a formula

Secant is usually abbreviated as "sec" as a trigonometry formula, as in the following equation:


As the reciprocal of cosine, it's equivalent to:


If you already have the secant ratio, you can use the inverse secant or arcsecant to find the angle.

After, find all the trigonometric functions and inverse trigonometric functions in one tool.



PK started DQYDJ in 2009 to research and discuss finance and investing and help answer financial questions. He's expanded DQYDJ to build visualizations, calculators, and interactive tools.

PK lives in New Hampshire with his wife, kids, and dog.

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