In an Acrobat form, I want the text to be a max of 10pt, but reduce to make it fit if necessary

[RP&S SS]

In an Acrobat form, I want the text to be a max of 10pt, but reduce to make it fit if necessary. Is this possible? 

[Thom Parker]

Make the field a 10pt height and set the size to auto. 

[RP&S SS]

thanks - unfortunately, and my apologies as I neglecetd to mention this originally, it's a multi line field

[Thom Parker]

I do not think there is a way to control the initial font size for an auto-size multiline textbox.   Acrobat defaults the initail text size to 12 point. But there is literally no rule for this, it's totally arbitrary, so other PDF viewers could start at a different size.  

[JR Boulay]

Same answer in centimeters:

[Tariq Ahmad Dar]

Hi @kevin Thorne @ Riverside,

Hi there, thank you for your question!

You’re correct in noting that you’re working with a multiline form field in Acrobat. You’d like the text to display at a maximum of 10pt but shrink as needed to fit the field. This is a great use case, and I’m happy to clarify what’s currently possible in Acrobat, as it has already been laid out by Experts.

Behavior of Multiline Text Fields in Acrobat:

When you enable auto font sizing for a field:

• The font will dynamically shrink to fit the entered text.

• However, Acrobat does not allow setting a maximum font size cap (e.g., 10pt) while still auto-sizing below that.

• If you set the font size manually to 10pt, it will remain fixed and will not adjust to fit longer input—it may clip or overflow instead. I am sure you know it already

What You Can Do:

Here’s what we recommend:

1. Enable Auto Font Size:

   • Open Prepare Form > Double-click your field.

   • Under the Appearance tab, set Font Size to Auto.

   • Under the Options tab, make sure Multiline is checked.

2. Adjust Field Size Visually:

   • Ensure the field height is enough to accommodate the number of lines you expect, so smaller font sizes aren’t needed too often.

3. Add a Hint or Tooltip (Optional):

   • For end users, it might help to include a small note like “Text will shrink to fit the box” to set expectations.

Advanced Option:

With scripting, it’s technically possible to approximate custom font scaling logic based on input length. But due to the limitations of font handling in form fields—and especially with multiline inputs—this approach can be unpredictable and isn’t officially supported across all environments.

~Tariq