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How To Find Field Dimensions To Use For FormFieldLocation Property In Adobe Sign REST API

How To Find Field Dimensions To Use For FormFieldLocation Property In Adobe Sign REST API

How do you find the dimensions and position of a field when using the Adobe Sign REST API `formFields` endpoint so that you can then programmatically set where someone is to sign on your custom PDF?

When you’re uploading a complete PDF document to Adobe Sign and programmatically setting where users are to sign using the `formFields` endpoint you need to set the `formFieldsLocation` property for each field which requires values for top, left, width, height and page number.

So how do you find the top and left distances in pixels for your field, along with its width and height?

Unfortunately, there’s nothing helpful in Adobe Sign’s edit PDF area that can help provide this detail. Instead you need to download Adobe Acrobat Pro.

Finding Field Properties Using Adobe Acrobat Pro

Thankfully there is a quick and easy way to get the information you need to set your fields, and all you need is Adobe Acrobat Pro.

Once you’ve got Adobe Acrobat Pro on your computer you will want to open it up and have a copy of your custom PDF document on hand. Open this document in Adobe Acrobat Pro.

Use Prepare Form Tool

From here click on the View menu item, then Tools and click on the Prepare Form item (or More Tools and then the Prepare Form item).

This will open up a new toolbar where you can add elements to your PDF. Adobe may already automatically detect where fields can go on your document, so you might see some boxes already on your PDF.

If there’s already a field set for where you want your signature panel to be on your PDF then right-click on the field and select Properties…

Find the field you want to set and right-click on it then select Properties…

A new modal window will pop up and to find the dimensions of the field and it’s location on the page click on the Dimension tab.

On the Text Field Properties window click on the Position tab to get all the dimensions

Here you can now get the dimensions and location of your field in inches. The reason why you need the values in inches is due to the type of measurement needed to place the signature panels. According to the Adobe Sign REST API documentation page:

Units of measurement: Positional parameters such as left, top, height and width are specified in this document in ‘default user space units’ (defined in the PDF specification; links follow). For practical purposes a default user space unit is equivalent to 1/72 of an inch independent of whether or not the originally uploaded document was a PDF file

Adobe Acrobat Sign Developer Implementation Notes

Therefore, write down the numbers in inches you see for the top, left, width and height values and for each value multiply it by 72 to get the user space units needed by Adobe Sign to set the location of your panels on your PDF document.

For example, if the top value of a field is located at 8.4933 inches then this converted to user space units equals 8.4933 x 72 = 611.5176.

Once you have all four values in user space units you can set the location field values.

If Adobe didn’t automatically add a text field to your PDF then you can click and select a text field in the Prepare Form tool bar.

If you can’t see the Prepare Form tool bar click on View then Show/Hide then Prepare Form.

Clicking on the Add text field button will allow you to place a text field anywhere on to your PDF. (It doesn’t matter what field you place as you just want the dimensions.)

You can then re-shape it as needed and then follow the process above in getting the right dimensions and properties of your field.

Click the text field button to add a field if Adobe doesn’t automatically set one


Creating a PDF document and sending it through Adobe Sign can be a great way to produce a workflow using digital documents.

However if you’re designing your document outside of Adobe and are not using templates then finding the dimensions of where to set your signature fields and other fields can be a pain.

As I’ve demonstrated in this post by using Adobe Acrobat Pro you can use the Prepare Form tool and obtain the dimensions using the properties of the field you’ve set.