ATAN2 in Zoho Sheet: Correct Angles for Every Quadrant

=ATAN2(x_coord; y_coord)

The official Zoho ATAN2 reference returns an angle in radians from the positive x-axis to the point (x_coord,y_coord), measured within (−π, π]. Examples in the documentation are =ATAN2(1;1) → approximately 0.785398163, =ATAN2(-2;3) → 2.15879893, and =ATAN2(3;-1) → −0.321750554. Use DEGREES for results in degrees. The signs and ordering in those worked examples provide strong evidence of Zoho’s coordinate convention.

ATAN2 is not a two-number version of ATAN for arbitrary pairs. It interprets the two arguments as Cartesian coordinates. If a function call uses x and y as separate values, the angle can be assigned to the correct quadrant even when the slope ratio y/x is negative in two different quadrants.

Enter the table below in a new workbook, keeping row 1 as headers. Column F is X_coord, and column G is Y_coord. Type the formula below into H2, then fill through H9. The table shows independently computed values rounded to six decimals, not actual native Zoho Sheet executions.

Step 1: Check the imported numeric F/G values and headings. Step 2: Enter =DEGREES(ATAN2(F2;G2)) into H2. Step 3: Fill H2 through H9, preserving the semicolon between the x and y arguments. Step 4: Format H as six-decimal numbers (or keep a separate display unit). Step 5: Compare rows 8 and 9 with the ATAN practice guide: plain ATAN of the quotient would return −45° and +45° respectively, not 135° and −135°.

For extra documentation cross-checks, type =ATAN2(-2;3) and =ATAN2(3;-1) into separate blank cells. Zoho’s official examples give approximately 2.15879893 and −0.321750554 radians; Python’s independent math.atan2(3,-2) and math.atan2(-1,3) agree to displayed precision. Do not write math.atan2(-2,3) if you mean Zoho’s ATAN2(-2;3): Python reverses the input order.

For a 2D site diagram, suppose F contains the eastward displacement and G the northward displacement. A Cartesian angle increases counterclockwise from east (positive x), while a compass bearing increases clockwise from north. Convert Zoho’s ATAN2 result to a 0°–360° compass bearing with:

=MOD(90-DEGREES(ATAN2(F2;G2))+360;360)

For F2=10, G2=0, this returns 90° (east); for F5=5, G5=5, it returns 45° (northeast); for F8=−4, G8=4, it returns 315° (northwest); for F9=−4, G9=−4, it returns 225° (southwest). For F=0, G=positive, it returns 0° (north). The +360 keeps the argument nonnegative before MOD and the final MOD normalizes the complete-circle result to 0–360 rather than allowing negative headings.

If both coordinates are zero, the direction does not exist geometrically. Zoho’s public ATAN2 page does not explicitly establish the error code returned for (0,0). A practical pattern to avoid evaluating an undefined heading is:

=IF(AND(F2=0;G2=0);"NO DIRECTION";MOD(90-DEGREES(ATAN2(F2;G2))+360;360))

This formula combines Zoho-documented function names but has not been run in Zoho Sheet; confirm the IF branch behaviour and configured separators in the editor. It is meant for planar coordinates with positive x=east and positive y=north. Real geographic bearings over long distances require geodesic methods and projection checks; latitudes and longitudes should not simply be treated as metres in a Cartesian plane.

A second application is plotting arrow directions in a dashboard. A point at (−2,+3) has a direction of 123.69° measured mathematically, even though its y/x ratio is −1.5. This allows a trend chart to show whether a change is toward the northwest rather than just whether a slope is positive or negative.

If you have only a ratio y/x, you generally cannot restore the quadrant unless you also know the signs of the source coordinates. When x=0, plain y/x is undefined; ATAN2 can represent points on the vertical axis (except the origin), which is another reason to prefer it for direction.

Microsoft’s Excel ATAN2 reference uses ATAN2(x_num,y_num) and documents #DIV/0! for both coordinates zero. Google Sheets ATAN2 also documents x then y. Their published argument order therefore agrees with Zoho’s in these references, although separator settings vary by locale and error handling should not be assumed identical. The especially important contrast is Python math.atan2(y,x), with y first. The independent calculations respect this conversion; Python did not evaluate a spreadsheet formula.

Reference check date: 2026-10-11. The official Zoho page does not provide a first-supported version, complete mobile-platform compatibility table, or account-tier matrix. No such historical or entitlement claim is made. Other spreadsheet or numerical libraries may expose different defaults for undefined or boundary cases.

Sources: Zoho ATAN2; Zoho DEGREES; Zoho MOD; Excel ATAN2; Google Sheets ATAN2. Independent results were computed with Python math.atan2(y,x) and math.degrees after respecting the opposite Python argument order. Native Zoho Sheet execution: NOT RUN.