The standard length of a text field is usually between 20-25 characters, but it can vary depending on the forms of the text field's purpose.
What is text field size?
The Text field is one of the most generic and common data entry fields used to capture text type data—letters, numbers, and symbols. Text fields hold up to 255 characters in a single line.
What is the default size for a text field?
The size attribute specifies the width of a text field (in number of characters). The default value is 20.