Office Chair Dimensions and Seat Fit

The office chair dimensions tool shows the seat height and seat depth to look for in an office chair, based on two seated body measurements, and lists the sizes of a typical office chair. You enter your floor-to-knee and hip-to-knee measurements, and the tool gives you the numbers to compare when you shop. It runs in your browser, is free, and needs no sign-up. Nothing is uploaded.

The figures come from a university guide, chair makers and a reference site. They are not a single official standard, so check the seat sheet for the chair you plan to buy. The tool also shows seat width, the chair’s overall size and the floor space it needs, and it works in inches or centimeters.

How to use the office chair dimensions tool

1. Choose a unit in the Units control: inches or centimeters. Pick this first so your numbers match.
2. Sit with your feet flat and measure from the floor to the back of your knee. Type the result into Floor to the back of your knee (seated). The starting value is 18 in.
3. Measure from your hip to the back of your knee while seated. Type the result into Hip to the back of your knee (seated). The starting value is 19 in.
4. Optional: open More options and type your height into Your height (optional). Leave it blank to skip the height result.
5. Read Seat height to look for and Seat depth to look for.
6. If you typed a height, read Seat height for your height.
7. Check Size of a typical office chair, Seat width and Floor space for the chair.
8. Scroll to the chart under the result. It lists the measurements by guide, labelled U, B, A and I. The second table names each guide.

The four preset buttons fill in values for you: Shorter, Starting values, Taller and Centimeters. The starting values are examples, not averages. If a field is empty, zero or not a number, the tool shows an error instead of a result.

What size is a standard office chair?

A standard office chair is about 27 in wide, 27 in deep and 47 in tall (69 x 69 x 119 cm), according to a moving-size reference. Its base is typically 26 to 27 in across, and the chair sits about 38 in tall at its lowest setting. These are typical figures, not a standard, so measure the chair you are considering.

Executive chairs can be wider, at 30 in or more.

What seat height should an office chair have?

An office chair seat should sit about 1 in lower than your floor-to-knee measurement. One chair maker uses the rule seat height = knee-to-floor minus 1 inch, so an 18 in measurement wants a 17 in seat. Measure from the floor to the crease behind your knee with your feet flat, and allow for the shoes you wear.

Adjustable office chairs typically run 16 to 21 in, according to a chair maker and a desk and chair maker. A university guide that quotes CSA gives 15 to 21 in (38 to 51 cm). The tool shows the 15 to 21 in range and adds a note if your figure is outside it. In that case, a short or tall gas cylinder may help, or a footrest if the seat sits too high.

How deep should an office chair seat be?

An office chair seat should be about 2 in shallower than your hip-to-knee measurement. The same chair maker gives examples: a hip-to-knee of 18 in wants a 16 in deep seat, and 21 in wants 19 in.

The university guide says to leave two to three fingers between the seat edge and the back of your knee. Most chairs ship fixed between 16 and 20 in deep. The university recommends a seat slider with a range of 15 to 20 in (38 to 50 cm). The tool adds a note when your figure falls outside the depths most chairs offer.

How much space does an office chair need behind a desk?

An office chair needs at least 42 in of depth behind the desk so it can roll back. This figure comes from a moving-size reference. The tool’s Floor space for the chair result shows this number along with the chair’s width and base.

Plan for the chair to move, not just sit still. Check the space behind the desk before you buy.

Can I use the tool in centimeters?

Yes. Select centimeters in the Units control, then type your measurements in centimeters. The Centimeters preset fills in a knee measurement of 46 and a hip-to-knee measurement of 48.

The CSA-based ranges are also given in metric. Seat height is 38 to 51 cm, and the recommended seat depth range is 38 to 50 cm.

Sources (checked 23 October 2026): uwo.ca, choosing a chair (CSA figures) · branchfurniture.com · autonomous.ai · itemfits.com

Worked examples

Calculated by the tool above; open it with the same values to see each step.

Frequently asked questions

What seat width should an office chair have?

A chair maker calls 18 to 20 in ideal. The university guide says the seat should not be under 18 in (45 cm). The desk and chair maker says a seat under 18 in compresses the hips, and over 22 in is excess unless you are broader than average through the shoulders.

What does the optional height field do?

It adds a Seat height for your height result. One chair maker suggests about 16 to 18 in for people under 5 ft 3 in (63 in), 18 to 21 in for people 5 ft 8 in (68 in) and over, and 16 to 21 in between those heights. At 60 in tall, the tool shows 16 to 18 in.

Why does the tool show an error or a warning?

An error appears if the floor-to-knee measurement is 1 in or less, the hip-to-knee measurement is 2 in or less, or a field is empty, zero or not a number. Warnings appear if the floor-to-knee is outside 12 to 30 in, the hip-to-knee is outside 14 to 28 in, or the height is outside 40 to 90 in.

What does the tool give for a taller person?

With a floor-to-knee of 21 in and a hip-to-knee of 21 in, the tool gives a seat height of 20 in and a seat depth of 19 in. Try the Taller preset to see this kind of result quickly.

Related tools

• Standard Desk Height: use it to find a typical desk height to pair with your chair.
• Standing Desk Height: use it if you plan to stand at your desk part of the day.
• Regular Desk Size: use it to check desk dimensions against the space your chair needs.
• Dining Chair Height for Your Table: use it to match a chair to a dining table.
• Bench Height and Size Calculator: use it to size a bench for seating.
• Tables and Seat Heights: use it to compare table heights with seat heights in general.