10 min

Measure Yourself in
10 Minutes.
Get a Better Evaluation.

Half of prospects skip or guess their body measurements when they book. That burns 15–20 minutes of a 60-minute eval just recapturing data. Take these 7 measurements at home first, and we spend the whole session on chair selection, fit tradeoffs, and pressure management — not tape-measure basics.

7 measurements
Tape measure + a helper (or a wall)
Printable worksheet
Written by Daryl Bullard, ATP

What you need

You don't need a clinical setup. Most people can do this solo, but a helper makes three of the seven measurements significantly easier.

Flexible tape measure

Fabric or plastic, at least 60 inches. The kind from a sewing kit works perfectly.

A firm, flat chair

Not a couch or recliner. A kitchen or dining chair with a hard seat gives the most accurate sit.

A helper (strongly recommended)

Hip width and seat depth are much more accurate with a second person holding one end of the tape.

Phone or notepad

Jot measurements as you go. You'll enter them in the intake form before booking.

~10–15 minutes

Do it in one sitting if possible. Fatigue posture vs. rested posture can shift measurements by ¾".

Printable worksheet

Download the one-page PDF below and fill it in as you go — or just use the section headers here.

Take these in order

Each measurement has a direct impact on frame sizing, seat configuration, and pressure management. Don't skip #7 — body weight drives axle placement and wheel camber more than most people realize.

1

Seat Width (Hip Width + Clearance)

Widest point of your hips or thighs, sitting

What it is
The widest horizontal distance across your hips or thighs while seated. Your chair's seat pan needs to be wide enough to accommodate this with a small clearance on each side — but not so wide it forces you to reach out for propulsion.
Why it matters
Too narrow = pressure on outer thighs and iliac crests. Too wide = shoulder abduction during propulsion (shoulder injuries over time), and a chair that won't fit through doorways. Ultralight chairs are often ordered ½" narrower than measured to achieve the optimal push stroke.
How to measure
  • Sit in your firm chair, feet flat on the floor
  • Relax — don't suck in or push out
  • Have helper run tape across the widest point of your hips or outer thighs
  • Record in inches
Common mistake

Measuring over thick pants or while holding your legs together. Wear thin clothing and let your legs fall naturally.

2

Seat Depth (Popliteal to Back of Buttock)

Back of knee to back of seat bone, minus 1–2"

What it is
The distance from the back of your knee (popliteal fold) to the back of your buttock (ischial tuberosities). Your actual seat depth order will be 1–2" shorter than this measurement to prevent pressure at the popliteal.
Why it matters
Too deep = front edge of seat presses behind the knee, cuts off circulation. Too shallow = insufficient thigh support, increased ischial loading. This is one of the measurements most often guessed wrong in online chair orders — and it causes real tissue damage over time.
How to measure
  • Sit against the back of your chair, back straight
  • Place one end of tape at the popliteal fold (crease behind the knee)
  • Extend straight back to the rearmost point of your buttock
  • Record in inches — we'll subtract 1–2" at the eval
Common mistake

Measuring to the back of the chair, not the back of your body. You're measuring you, not the furniture.

3

Back Height

Seat surface to desired back support termination point

What it is
The vertical distance from the seat surface up to where you want the top of the back support to end. This varies significantly based on trunk stability, activity level, and propulsion style.
Why it matters
Active propellers often want low backs (below the shoulder blade) to allow full trunk rotation. People with less trunk stability need higher backs. Getting this wrong doesn't just affect comfort — it affects your propulsion efficiency and fatigue over the course of a day.
How to measure
  • Sit upright in your firm chair
  • Locate the bottom of your shoulder blade (inferior angle of scapula)
  • Measure from seat surface up to that point
  • Also note your axilla height (armpit height seated) for reference
Common mistake

Measuring to the top of the shoulder. That's the axilla measurement. Your back height is almost always 2–4" below the shoulder tip.

4

Lower Leg Length (Seat to Heel)

Popliteal fold to bottom of heel

What it is
The vertical distance from the back of your knee crease (popliteal) down to the bottom of your heel. This determines your footrest height — you want your thighs parallel to the floor (or slightly forward tilted) with no gap under the thigh.
Why it matters
Footrests set too high shift weight backward onto the ischials and sacrum. Footrests set too low leave the thighs unsupported and force the body forward. Either is a pressure-injury risk. This measurement also interacts with seat dump angle and overall chair height.
How to measure
  • Sit with feet hanging naturally (no floor contact)
  • Measure from the popliteal fold straight down to the bottom of the heel
  • Wear whatever footwear you'd normally use in the chair
  • Record in inches
Common mistake

Measuring with feet flat on the floor. The popliteal-to-heel distance needs to be a free-hanging measurement — not compressed by bearing your weight.

5

Trunk Width

Widest point of your torso at the seat back contact zone

What it is
The widest horizontal measurement of your trunk in the region where the back support contacts your body — typically measured at the ribs or waist level, not the shoulders.
Why it matters
Informs lateral support placement and back width. If you need lateral trunk supports (for scoliosis, poor trunk control), this measurement defines where they start. It also influences whether a sling back or rigid back is more appropriate for your anatomy.
How to measure
  • Sit upright, arms relaxed at sides
  • Measure horizontally at the level of your lowest rib
  • Then measure at your narrowest waist point
  • Record both — back design depends on which point needs support
Common mistake

Confusing trunk width with seat width. Seat width is your hips. Trunk width is your torso — usually smaller, and used for back hardware, not the seat pan.

6

Hip Width (Sitting, Widest Point)

Outer hip bone to outer hip bone, seated

What it is
The bony width across your pelvis — outer iliac crest to outer iliac crest — while seated. This is slightly different from seat width measurement #1, which captures soft tissue (thigh width). Hip width is the skeletal measurement that constrains minimum seat width on a rigid frame.
Why it matters
On ultralight rigid chairs, the seat width can't be smaller than your hip width without causing bone-on-frame contact. This is the floor measurement. Seat width (measurement #1) is usually ½–1" larger than this. If there's a big gap between the two, that gap is soft tissue — relevant for cushion selection.
How to measure
  • Sit upright, feet flat
  • Palpate (feel) the prominent bony points on each outer hip
  • Measure tape straight across from point to point
  • Keep tape level, not following the curve of the hip
Common mistake

Measuring at the widest soft-tissue point and calling it hip width. You want the bony landmarks specifically — the prominent iliac crests you can feel clearly through your skin.

7

Body Weight

Current weight, lbs or kg — with shoes and typical clothing

What it is
Your current body weight. Simple — but often under-reported or estimated from years ago. Your actual weight affects more than you'd expect on a custom-fit manual chair.
Why it matters
Weight drives axle position (heavier = axle moves back for stability), wheel camber selection, frame tube wall thickness, and component load ratings. It also affects whether a given lightweight chair will remain under your target propulsion weight with your cushion added. Don't guess — step on a scale.
How to measure
  • Use a standard bathroom scale
  • Weigh with your shoes on if you wear them in the chair
  • Morning weight is typically most consistent
  • Note if your weight fluctuates significantly (edema, etc.)
Common mistake

Using a weight from your last doctor visit or "roughly" estimating. An error of 15 lbs can shift axle recommendations by ½". Just weigh yourself today.

What else to have ready

Measurements unlock the hardware conversation. This context unlocks everything else — your sitting history, pain points, and daily demands drive the final recommendation as much as the numbers.

Current chair make, model, and year

If you have a current chair, knowing what it is — and what you hate about it — is faster than starting from scratch. Check the side frame or look up the serial tag.

Pressure sore history

Any history of pressure injuries (location, severity, whether healed) directly affects cushion selection and seat dump angle. Don't skip this — it's the most medically critical variable.

Current cushion type

Foam, air, gel, hybrid — and whether it's working for you. If you're unsatisfied with your current cushion, that's often the fastest win in the entire eval.

Daily sitting hours

Are you in the chair 2 hours a day for mobility, or 14 hours as your primary seating? This changes the entire pressure management and back support calculus.

Transfer style

Independent or assisted? Sliding board, stand-pivot, lift? Your transfer technique affects armrest configuration, seat height from floor, and whether a rigid or folding frame makes more practical sense.

Primary environments

Mostly indoors on smooth floors, or outdoors on pavement, grass, or rough terrain? Wheel size, tire width, and anti-tip positioning all depend on where you actually roll.

Printable Measurement Worksheet

One-page PDF. Blank fields for all 7 measurements plus the contextual info above. Print it, fill it in while you measure, then keep it on hand for your evaluation. No email required.

Download PDF

Measurements done?
Book the eval.

A 60-minute telehealth session with Daryl Bullard, ATP — 20+ years fitting ultralight manual chairs, zero brand commissions. The $200 fee is credited in full toward any chair purchase. Come in with your measurements and we'll go deep.