Human Factors Guidelines

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You can increase the comfort and safety of your work environment, and decrease your chances of cumulative trauma disorder, by following the guidelines given below.

Also check out Take Ten for tips for adjusting your work area, and information on safe work habits and exercises for your neck, shoulders, wrists, and hands.

ANSI Standards for Visual Display Terminal (VDT) Workstations

Table 1 shows recommended guidelines for furniture and system adjustment, as developed by the American National Standards Institute (ANSI).*

Local VDT guidelines issued by country, state, or municipality may apply and supersede the guidelines in Table 1.

Table 1 - ANSI/HFS 100-1988 Guidelines for VDT Workplace Adjustment

Adjustment Small Female
cm (in)
cm (in)
Large Male
cm (in)
Seat pan height 40.6 (16.0) 46.3 (18.2) 52.0 (20.5)
Work surface height (keyboard
and mouse
58.5 (23.0) 64.75 (25.5) 71.0 (28.0)
Screen viewing height >30.5 (>12) >30.5 (>12) >30.5 (>12)
Screen viewing angle 0-60 degrees 0-60 degrees 0-60 degrees

Adjustment parameters are defined in the following illustration. Guidelines are shown for small females (standing height of 150 cm or 59 in.) and large males (standing height of 185 cm or 73 in.). Midpoints are also interpolated for persons of more average height.

Basic Parameters of VDT Workstation Adjustment

(Adapted from ANSI/HFS 100-1988)

Computer Aided Design (CAD) Operator Preferences

If you work on a CAD system, you may feel more comfortable using the ranges of adjustment shown in Table 2.

Table 2 - Workstation Adjustment Preferred by CAD Users

Adjustment Mean
cm (in)
cm (in)
Seat pan height 54 (21.3) 50-57 (19.7-22.4)
Work surface height 73 (28.7) 70-80 (27.6-31.5)
Monitor center above floor 113 (44.5) 107-115 (42.1-45.3)
Screen viewing distance 70 (27.6) 59-78 (23.2-30.7)
Work surface tilt 8.6 degrees 2-13 degrees
Monitor tilt -7.7 degrees -15 - + degrees


* American National Standard for Human Factors Engineering of Visual Display Terminal Workstations. ANSI/HFS 100-1988. Available through the Human Factors Society, Inc.,
P.O. Box 1369, Santa Monica, CA, 90406, USA.