Arcsin calculator
Enter a number between −1 and 1 and get the angle whose sine it is, in degrees or radians. For example sin⁻¹(0.5) = 30°.
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 does arcsin do?
Arcsin (also written sin⁻¹ or asin) works backwards: you know the sine and want the angle. Because many angles share the same sine (sin 30° = sin 150°), the calculator gives the principal value, which lies between −90° and 90°.
Why only between −1 and 1?
A sine is never smaller than −1 or larger than 1, so arcsin(2) doesn't exist. You get a message instead of a strange answer. For the other inverse functions, use the arccos and arctan calculators.
Frequently asked questions
Is the arcsin calculator free?
Yes. The arcsin 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.