12.2.1.1.2-3 Character Height

Characters used on labels should be sized to take into account viewing distances and illumination conditions.

Additional Information: Table 12.5 gives character heights required for various viewing distances. Under less-than-optimal viewing conditions, the preferred values should be used as minima. The preferred values should also be used for critical markings associated with safety-related systems.6146

 

Table 12.5 Minimum And Preferred Character Heights For Various Viewing Distances

 

Viewing Distance

Minimum Character Height

Preferred Character Height

feet (m)

inches (mm)1

points2

inches (mm)3

points2

2.33 (0.71)

0.11 (2.84)

8

0.17 (4.27)

12

3 (0.91)

0.14 (3.56)

10

0.22 (5.49)

16

4 (1.22)

0.19 (4.88)

14

0.29 (7.32)

21

5 (1.52)

0.24 (6.10)

17

0.36 (9.14)

26

6 (1.83)

0.29 (7.32)

21

0.43 (10.97)

30

10 (3.05)

0.48 (12.19)

35

0.72 (18.29)

50

20 (6.10)

0.96 (24.38)

70

1.44 (36.58)

100

30 (9.14)

1.44 (36.58)

100

2.16 (54.86)

150

40 (12.19)

1.92 (48.77)

140

2.88 (73.15)

200

  1. minimum character height (15minutes of arc) = distance multiplied by .004
  2. character heights in points (1 point = 1/72 inch = 0.35 mm) are approximate
  3. preferred character height (20 minutes of arc) = distance multiplied by .006