Tangent calculator
Enter an angle and get its tangent straight away, with the exact value for special angles such as tan(45°) = 1.
In degrees or radians (choose above).
Fill in the fields; the answer appears here straight away.
How it's worked out
How it works
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Enter the values
Type the numbers or the formula. Decimals may use a point or a comma. No idea? Click Fill in an example.
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Instant answer
The answer appears as you type, with the most important intermediate values.
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See the working
Under "How it's worked out" you see the steps, handy for checking your own calculation.
What is the tangent?
In a right-angled triangle, the tangent of an angle is the opposite side divided by the adjacent side. It is also sine divided by cosine. That is why the tangent doesn't exist at 90° and 270°: the cosine is 0 there, and the calculator tells you so.
Degrees or radians
Enter the angle in degrees or radians (choose above). Expressions such as pi/3 or 2pi/5 work too.
Useful values
tan(0°) = 0, tan(30°) = √3/3 ≈ 0.577, tan(45°) = 1 and tan(60°) = √3 ≈ 1.732. To find an angle from its tangent, use the arctan calculator. For a triangle with two known sides, use the right triangle calculator.
Frequently asked questions
Is the tangent calculator free?
Yes. The tangent calculator is completely free, with no account, sign-up or usage limit.
How accurate is the result?
The tool calculates with your browser's number precision. For important calculations, always double-check what you entered.
Does it work on my phone?
Yes. The tool works in any modern browser on a phone, tablet or computer.