topic Re: Field scale not working with double type when adding a new field in ArcGIS Pro Questions

Field scale not working with double type when adding a new field

Juanv1927 — Tue, 04 Nov 2025 15:15:54 GMT

Hi everyone,

I’ve been trying to add a new field to my shapefile and have been struggling to set the precision and scale. I need a Double data type with a scale of 2 and the default precision, but every time I try, I either get an error message, or the field automatically changes to Float.

I’ve tried several approaches—adding the field directly in the attribute table, using Add Field in ArcGIS Pro, and even exporting it back to a geodatabase—but the same issue persists.

I’ve read mixed information online about whether scale is supported in shapefiles, and I’m not sure what to believe at this point.
Has anyone managed to make this work, or can confirm if it’s simply not supported?

Thank you all! 🙂

Re: Field scale not working with double type when adding a new field

HaydenWelch — Tue, 04 Nov 2025 21:05:48 GMT

Here's the dBase file spec. Seems that there are flags for precision and length. Have you hovered over the red square to see what the error is? I just added a high precision Double field to a shapefile dbf on my end so I'm wondering what the error says.

1. 2 Field Descriptor Array

Byte	Contents	Description
0-31	32 bytes	Field name in ASCII (zero-filled).
32	1 byte	Field type in ASCII (B, C, D, N, L, M, @, I, +, F, 0 or G).
33	1 byte	Field length in binary.
34	1 byte	Field decimal count in binary.
35-36	2 bytes	Reserved.
37	1 byte	Production .MDX field flag; 0x01 if field has an index tag in the production .MDX file; 0x00 if the field is not indexed.
38-39	2 bytes	Reserved.
40-43	4 bytes	Next Autoincrement value, if the Field type is Autoincrement, 0x00 otherwise.
44-47	4 bytes	Reserved.