Written and maintained by CASRAI Editorial Board
Last updated
General product information only, not medical advice. Follow the label or instructions for use supplied with the specific sling and the advice of the treating clinician.
Sling sizes are set by each manufacturer, not by a standard. The same label (Small, Medium, Large) covers different measurements from one maker to the next, and different makers ask you to measure different things: forearm length, forearm from fingertip, or chest circumference. The charts below show three published examples side by side, each attributed to the company that published it. Use the chart that belongs to your product, not the one that looks closest.
This page covers medical arm slings and shoulder immobilizers. Patient-lift slings (the fabric seat or harness used with a lift) are sized differently; see what a patient lift is. Climbing, baby-carrier and firearm slings are separate products.
Arm sling size chart (forearm length)
Two manufacturer charts measure the forearm, but not from the same points, so the numbers are not interchangeable.
| Size | AliMed Open End Arm Sling: forearm, elbow to base of little finger | Same range in cm (converted) | Ossur padded strap shoulder immobilizer sling: forearm, fingertip to elbow, as listed by an Australian distributor | Same limit in inches (converted) |
|---|---|---|---|---|
| XS | not listed | not listed | up to 28 cm | up to 11.0 in |
| Small | 11 in to 13 in | 27.9 to 33.0 cm | up to 34 cm | up to 13.4 in |
| Medium | 13 in to 14 in | 33.0 to 35.6 cm | up to 39 cm | up to 15.4 in |
| Large | 14-1/2 in to 15-1/2 in | 36.8 to 39.4 cm | up to 44 cm | up to 17.3 in |
| X-Large | 15-1/2 in and over | 39.4 cm and over | up to 50 cm | up to 19.7 in |
Conversions use 1 inch = 2.54 cm and are rounded. The original figures are the ones in the manufacturer columns. AliMed lists its sling as fitting the left or right arm.
Shoulder immobilizer size chart (chest circumference)
AliMed sizes its Shoulder Immobilizer with Body Strap by chest circumference, not by arm length.
| Size | Chest circumference (AliMed, inches) | Converted to cm |
|---|---|---|
| Small | 24 in to 30 in | 61 to 76 cm |
| Medium | 30 in to 36 in | 76 to 91 cm |
| Large | 36 in to 40 in | 91 to 102 cm |
| X-Large | 40 in to 44 in | 102 to 112 cm |
Check your product’s labelling. These are examples from three product listings, not a universal chart. Your sling’s own size chart or instructions for use decide the size.
How to read the charts
Find out first which measurement the maker asks for, then read across that maker’s own row. The two arm-length charts above show why: AliMed measures from the elbow to the base of the little finger, while the Ossur listing measures from the fingertip to the elbow. A fingertip-to-elbow length is longer than an elbow-to-little-finger-base length for the same arm, so a Medium in one chart is not a Medium in the other. As published, AliMed Medium is 13 to 14 in (about 33 to 36 cm) while the Ossur Medium limit is 39 cm (about 15.4 in).
Each AliMed range is a band between two figures, while the Ossur figures are upper limits (each size is listed as “to” a length). AliMed’s Medium ends at 14 in and its Large starts at 14-1/2 in; the chart does not say which size covers the half inch between, which is a reason to read the maker’s own instructions rather than rounding yourself.
How to measure, as each maker states it
- AliMed Open End Arm Sling: “Measure forearm from elbow to base of little finger.”
- Ossur padded strap shoulder immobilizer sling (distributor listing): measure forearm length from fingertip to elbow.
- AliMed Shoulder Immobilizer with Body Strap: “Measure chest circumference. Women measure just below bustline; men measure chest at widest point.”
These instructions apply to the named products. Another brand may state a different rule, so follow the instructions for use supplied with your product.
Why S, M and L differ between brands
In the United States an arm sling is defined by the FDA as “a device intended for medical purposes to immobilize the arm, by means of a fabric band suspended from around the neck” (21 CFR 890.3640). It is a Class I device exempt from premarket notification. The regulation defines what the device is and sets no size table. Sizing therefore comes from each manufacturer’s design, which is why the same letters map to different ranges.
The types of slings guide covers the other sling designs.
Common mix-ups
- Patient-lift slings. Charts that rank high for “sling sizes” are often for patient-lift slings. Those use different measurements and are not for an arm sling.
- Inches versus centimetres. Charts from United States sellers use inches, the Ossur listing uses cm. 1 in = 2.54 cm.
- Arm length versus chest size. A shoulder immobilizer with a body strap may be sized by chest circumference, not by the arm.
- Different start and end points. Elbow to little-finger base and fingertip to elbow are different lengths.
- Sling versus splint or brace. A splint, a clavicle or back brace and a cervical collar each follow their own maker’s sizing.
FAQ
Is there a standard arm sling size chart?
No. The FDA regulation (21 CFR 890.3640) defines the device but gives no sizes. Each manufacturer publishes its own chart, so use the one for your product.
What are typical arm sling sizes?
Makers commonly label sizes from Small to X-Large, and some add XS. The ranges differ: for example AliMed lists Small as a forearm of 11 in to 13 in, and an Ossur listing gives Small as up to 34 cm.
How is a shoulder immobilizer sized?
AliMed’s Shoulder Immobilizer with Body Strap is sized by chest circumference, from Small at 24 to 30 in to X-Large at 40 to 44 in. Other models may be sized by arm length, so follow your product’s label.
Is there a clavicle brace size chart?
Clavicle braces are a separate product from slings and immobilizers, and the charts on this page do not apply to them. Use the size information supplied with the specific brace; see back brace types for how they are classified.
Can I use inches from one chart on a centimetre chart?
Only if both charts measure the same thing. Convert with 1 in = 2.54 cm, then confirm both makers measure from the same points.
Where can I find slings by category?
Browse emergency and trauma supplies and check each product’s own sizing information.
Sources
- AliMed, Open End Arm Sling, sizing information: https://www.alimed.com/products/alimed-open-end-arm-sling (checked 2026-10-30)
- AliMed, Shoulder Immobilizer with Body Strap, sizing information: https://www.alimed.com/products/shoulder-immobilizer-with-body-strap (checked 2026-10-30)
- APE Medical (Australian distributor), Ossur Padded Strap Shoulder Immobilizer Sling: https://www.apemedical.com.au/product/ossur-padded-strap-shoulder-immobilizer-sling/ (checked 2026-10-30)
- 21 CFR 890.3640, Arm sling: https://www.law.cornell.edu/cfr/text/21/890.3640 (checked 2026-10-30)
