FAQ

Last updated:July 8, 2026

Common questions about ATAN usually involve parameter types, result interpretation, and filling formulas across cells; this section covers 3 frequent questions.

FAQ

What should I do if ATAN returns an error?

  1. Check whether the parameter is numeric or whether the referenced cell contains text or extra spaces.
  2. Confirm that the function name, parentheses, and formula structure are entered correctly.
  3. Clean the source data if needed, then enter the formula again.

Why does the ATAN result not match the angle I expected?

  1. Confirm that the returned result is in radians rather than degrees.
  2. Check whether the input value and cell references are correct.
  3. If you need degrees, convert the result in a later step.

How can I use ATAN in multiple cells at once?

  1. Enter the correct ATAN formula in the first target cell.
  2. Select that cell and drag the fill handle across the target range.
  3. After filling, check whether relative or absolute references need adjustment.

Glossary

TermDefinition
ATANAn inverse tangent function that returns the arctangent of a numeric value.
RadianA unit used to express angles and commonly used as the return value in trigonometric functions.
ParameterThe input inside a function's parentheses. ATAN requires one numeric parameter.
Formula barThe area above the worksheet where you can enter or edit formulas directly.
Fill handleThe small square at the lower-right corner of a selected cell, used to copy formulas across a range.