What is the syntax for ASIN in Excel?

The syntax for ASIN is: =ASIN(number)

What are common errors with ASIN?

#NUM! if number outside -1 to 1

What is ASIN (arcsine)?

ASIN is the inverse of SIN - it returns the angle whose sine is the given number. If SIN(30°)=0.5, then ASIN(0.5)=30° (in radians: π/6 ≈ 0.524). Input must be between -1 and 1.

What is the range of ASIN output?

ASIN returns values from -π/2 to π/2 radians (-90° to 90°). This is the principal value. For angles outside this range, you may need to adjust based on the quadrant of your original problem.

How do I find an angle in a right triangle using ASIN?

If you know opposite side and hypotenuse: angle = ASIN(opposite/hypotenuse). Example: opposite=3, hypotenuse=5, angle = DEGREES(ASIN(3/5)) = 36.87°. This is the angle opposite the known side.

Math & Trig

ASIN Function in Excel

Returns the arcsine of a number in radians.

Syntax

=ASIN(number)

Arguments

number (required): Sine value (-1 to 1)

Examples

=ASIN(0.5) - Arcsine of 0.5 - Result: 0.524 (π/6)

ASIN in reporting workflows

Use absolute references when copying formulas across rows.
For conditional totals see [SUMIF](/functions/sumif/) and [SUMIFS](/functions/sumifs/).
Filtered lists may need [SUBTOTAL](/functions/subtotal/) instead of SUM on visible cells only.

Common errors

#NUM! if number outside -1 to 1

Use cases

Trigonometry
Angle calculations
Engineering

Frequently asked questions

What is ASIN (arcsine)? ASIN is the inverse of SIN - it returns the angle whose sine is the given number. If SIN(30°)=0.5, then ASIN(0.5)=30° (in radians: π/6 ≈ 0.524). Input must be between -1 and 1.
What is the range of ASIN output? ASIN returns values from -π/2 to π/2 radians (-90° to 90°). This is the principal value. For angles outside this range, you may need to adjust based on the quadrant of your original problem.
How do I find an angle in a right triangle using ASIN? If you know opposite side and hypotenuse: angle = ASIN(opposite/hypotenuse). Example: opposite=3, hypotenuse=5, angle = DEGREES(ASIN(3/5)) = 36.87°. This is the angle opposite the known side.

Editorial review

Reviewed by Excel.Directory Editorial Team. Updated May 2026.