Print Comparisons

By: Carmen Willings
teachingvisuallyimpaired.com
​Updated June 14, 2025
I frequently use environmental print comparisons to help team members understand the relationship between a student's near visual acuity and accessible font sizes. This is especially helpful when discussing accommodations for students with low vision.
It’s important to note: although a student may be able to see a smaller font (their visual threshold), this does not mean it is a functional or efficient size for reading sustained text. The most appropriate font size is the smallest one the student can read easily, accurately, and fluently over extended periods.

Near Vision Snellen Test Chart with Environmental Print Comparisons

The following chart correlates Snellen acuity with typical print sizes and real-world examples:
Jaeger
​Equivalent
M
Acuity
Print Size Comparison
Example
Value
0.4
20/20
 3 pt font
medicine bottle labels
J1
0.5
20/25
4 pt font
mail order catalogs
J2
0.6
20/30
5 pt font
small print Bible; footnotes
J3
0.8
20/40
6 pt font
want ads; telephone directory
J5
1.0
20/50
8 pt font
small column newsprint
J7
1.2
20/60
10 pt font
paperback books; newsprint
J10
1.3
20/65
12 pt font
Grade 4-7 children's books
-
1.6
20/80
14 pt font
Grade 1-3 children's books
-
2.0
20/100
16 pt font
computer display type
-
2.15
20/108
18 pt font
Pre-K/K Children's books
J12
2.5
20/125
20 pt font
Books for ages 7-8
J14
3.0
20/150
24 pt font
Large Print Books
J15
4.0
20/200
33 pt font
Sub-headlines; children's books
J16
8.0
20/400
66 pt font
Newspaper headlines
Source: Low Vision Clinic, N.C. Memorial Hospital, Dept. of Ophthalmology, UNC School of Medicine, Chapel Hill, NC.

Functional Distance Acuity Approximations (at 20 feet)

This table compares gross object size and minimum detail size with approximate Snellen acuity at a standard viewing distance of 20 feet:​
Gross Sizes (Observable overall size of an item)
Snellen Equivalent
Minimum Sizes (separation, detail sizes)
Snellen Equivalent
3/8"
20/20
1/16"
20/20
7/16"
20/25
.
.
1/2"
20/30
1/8"
20/30
3/4"
20/40
3/16"
20/40
1"
20/60
1/4"
20/60
1 1/2"
20/80
5/16"
20/80
1 3/4"
20/100
7/16"
20/100
2"
20/120
1/2"
20/120
2 7/16"
20/140
9/16"
20/140
2 3/4"
20/160
11/16"
20/160
3 1/4"
20/180
.
.
3 1/2"
20/200
13/16"
20/200
4 1/4"
20/225
.
.
5 1/4"
20/300
15/16"
20/300
6 3/4"
20/350
1"
20/350
7 1/8"
20/400
1 3/16"
20/400
10 1/2"
20/600
1 1/2"
20/600
12"
20/700
1 5/8"
20/700

​Approximating Functional Visual Acuity (for Nonverbal Students)

For students who are nonverbal or cannot participate in standardized visual acuity testing, functional acuity may be approximated by comparing the size of the object a student can recognize and the distance from which it is viewed:
Object Size
2 feet
4 feet
6 feet
8 feet
20 feet
1/4"
20/200
20/100
20/67
20/50
20/20
1/2"
20/400
20/200
20/133
20/100
20/40
3/4"
20/600
20/300
20/200
20/150
20/60
1"
20/800
20/400
20/267
20/200
20/80
Source: Topor, I. (2004). Early Intervention Training Center for Infants and Toddlers With Visual Impairments, UNC-CH.

Tools for Estimating Font Size

Typesetter Ruler (e.g., C-Thru Flexible Typesetter’s Ruler)
  • Made of clear plastic
  • Includes font size samples, pica, point, inch, and line spacing measurements
  • Useful for overlaying printed materials to determine font size and spacing
  • Included in APH’s NewT Kit
Typometer
  • Printable typometer PDF printed on acetate
  • Can be placed over printed materials to determine font size directly
  • Similar typometers can be found via online searches or Pinterest
  • A helpful, low-tech resource for vision professionals and teachers
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