Size and fit

These are starting measurements for a quote, not a seating assessment. An ultralight, a tilt chair, a pediatric chair, or any chair someone sits in all day should be checked by a clinician.

Seat width

Sit on a firm chair. Measure the widest point across the hips or thighs and add about an inch. A winter coat counts if you wear it in the chair. Too narrow and you get pressure at the hips. Too wide and you push with your arms in a bad position and the chair misses doorways for no benefit.

Seat depth

Measure from the back of the pelvis to the back of the knee, then take off about one to two inches so the front edge does not press into the calf. Too long and the rider slides forward. Too short and the thighs are not supported.

Seat-to-floor

This includes the cushion. Feet should sit flat on the footplates, not dangle and not jack the knees up. Front and rear height can differ. That difference is how ultralights set the seat angle, and it is why “18 inch seat” is not a complete order.

Overall width and doorways

Many Canadian interior doors are about 30 to 32 inches. The chair’s overall width, including wheels and camber, has to clear the narrowest one. Write that number on the request.

Weight capacity

The rating includes the rider and what is carried: a bag, a tray, a vent. Being under the number is the requirement. Being far under it, in a huge chair, is its own problem.