Author's Note: In 2011 I coauthored an article here in The Ergonomics Report™, Is There An Industry Standard For Desk Height?, with Gene Kay. Soon after, a discussion erupted in one of the LinkedIn discussion groups, debating the very same topic. This article picks up from there ...

In our original article, we note that facility managers are one of the forces behind the persistent "29 inch standard desk height:"

Have you ever been asked 'what's the right height for my desk?' To the computer user, this is a simple question demanding a simple answer. To the ergonomist, it's a loaded question, one that requires a patient explanation of the factors that must be considered when setting up a workstation -- including desk height. To the furniture, facilities management and purchasing industries, it's "29 inches," which ergonomists know can't possibly be right for all people ...

So, I was especially interested to see this question raised by none other than a facility management professional, Dayn Muzzy, who asked:

Attn: Ergonomists: I have noticed that the industry standard for setting desk height is 29". Based on the Anthropometric data I have seen, this does not seem to correlate with mean US pop data?

I'll spare you the multiple long-winded responses his question drew, and cut directly to the heart of the discussion: Where does the 29 inch figure come from, and is it correct? I'll start with the "is it correct" part by sharing a few more excerpts from our original article:

The question got us thinking: asking 'what is the standard desk height' is like asking 'what is the standard waist size for a pair of pants.' Because we are ergonomists and we know that one-size does not fit all, we would laugh at such a question about clothing sizes, but somehow we accept the same type of absurd question when it comes to workstation design.

So, is 29 inches the correct height for an office desk? Absolutely not, unless you are "tall", or unless you add a footrest, adjustable keyboard surface, and any other number of band-aids to modify the workstation to fit a majority of users. Further, as some commenters dutifully explained, the nature of the work being performed, environmental factors, etc. must be taken into account before settling on a one-size-fits-all figure (for example thoughts on "one size fits all," read Commentary: Airline Seating -- One Size Does Not Fit All, or How to Choose a Stand Up Desk for guidance on adjustment ranges).

Here's more of what Gene Kay and I wrote about a 29 inch standard desk height:

There are a lot of reasons for a "standard desk height," the least of which, unfortunately, has anything to do with the health or performance of the person/people that will use the workstation. For example, establishing a standard one-size-fits-all height for computer workstation desk heights is a 'good idea' from these perspectives:

• It's easier and cheaper to manufacture static workstations
• It's easier and cheaper, at least up front, to purchase static workstations
• It might be easier to install static workstations
• It just so happens that things like under-the-desk file cabinets will fit under a 29" desk
• It has the word "standard" tied to it, so it gives decision makers (an unfounded) feeling of security

Notice that not one of these reasons is user centered. Not one of them takes into account the person; no concern for their performance; no concern for their health; and, therefore, little concern for long-term organizational performance, either. Not one of these reasons has any foundation in ergonomics theory or application.

This is where, I admit, we took some liberties. There is ergonomics theory and application that suggests 29 inches may be an agreeable height, but only if we first accept a "one-size-fits-all" compromise. That, however, is where I have a problem. Is it right, especially for professional ergonomists, to idly stand by when others promote a one-size-fits-all solution that we well know will not "fit all"? Or, is it our responsibility to inform, educate -- and drag kicking and screaming when necessary -- proponents of ergonomically poor compromises? If we don't advocate good ergonomics, who will!?

So, 29 inches actually represents a one-size-fits-all, significant compromise, and if we must compromise away good ergonomics, we should at least maintain some semblance of ergonomics by making that single solution as protective as possible. This is where the ergonomics theory comes into play, and the point where designers often make serious mistakes, and the point that caught the attention of the facility manager who posed the question. The "common sense" solution, if we can pick only one number for desk height, is to select the average seated elbow height, or a little below, right? Design for the average and you'll fit the most people, right?

Wrong. (This is one reason I often quietly bristle when people suggest "ergonomics is common sense.")

Ergonomics theory, drawing on our anthropometry knowledge base in this case, leads us to design for the extremes, not the average. Think of a doorway height. If we design it for the average height person, half the users would be forced to bend down to safely pass through. If we design it for the taller members of our population, however, all those who are as tall or shorter can safely pass through. For an example where we design for the smaller extremes, think of a machine guard. If we can keep smaller hands or fingers from passing through the guard openings, we will also protect those with larger hands and fingers.

Likewise, in the case of desk height, if we design it for the average height person, all those taller than average would have to somehow scrunch/slouch down to fit the station -- or not be able to fit at all. So, we design it for the taller population, and the rest of us can still fit by raising certain key dimensions using footrest, keyboard trays, old books, etc. That is, most users will require some sort of accommodation, but at least it will be possible, with some finessing, to fit everyone.

Actually, not everyone, because we make another compromise when it comes to designing for the extremes. We often leave out 10% of the population by selecting the 5th through 95th percentiles as our design population, leaving out the taller and smaller extremes. This is done for practical, economic reasons, as are the one-size-fits-all compromises. Not coincidentally, 29 inches represents an appropriate desk height for 95th percentile seated elbow height USA males. It clearly does not apply to all working populations across all regions of the world, and, as the LinkedIn discussion demonstrates, doesn't seem to work all that well even in the USA.

Adjustable worksurface technology exists. An adjustable worksurface usually eliminates any need for an add-on adjustable keyboard tray; eliminates the need for a footrest; eliminates the need for a custom fitting session with the local ergonomist; and eliminates the need for maintenance to come by and re-adjust a 29 inch desk height to one more appropriate for the specific user. Plus, there can be productivity, quality and morale gains, as well as reduced discomfort, pain and injury, all of which contribute to the economic justification. 

In other words, spend up-front to purchase an effective user adjustable system, or spend later, perhaps much more, to accommodate a poor one-size-fits-all compromise requiring multiple, costly band-aids. It's much about economics, so sharpen your pencil!

Fortunately, adjustable desks have become very affordable, and static desk heights will become a thing of the past, as will the question "what is the right desk height." Adjustable worksurfaces become recognized as standard, and the distinction between sitting and standing workstations is fading, and sit-to-stand solutions are becoming commonplace.

For more on stand-up workstations see our article How to Choose a Stand Up Desk.