What do S, SB and SM mean in para swimming?
B · Beginner · Classes and events · 2 of 2Each swimmer has a class for each stroke group: S for freestyle, backstroke and butterfly, SB for breaststroke and SM for medley. Physical classes run from S1, the most limited, to S10, with SB1 to SB9; SM is worked out from the S and SB classes. S11 to S13 are vision classes and S14 intellectual.
How it works
- S1 to S10: physical impairment; S1 most limited.
- SB1 to SB9: breaststroke; there is no SB10.
- SM: calculated from S and SB.
- S11 to S13: vision impairment, all strokes.
- S14: intellectual impairment.
- Points: physical classes come from a point score in assessment.
- Not eligible: swimmers who lose too few points.
- Class change: observation or a protest can change it mid-meeting.
The glossary has the S1 to S10, the SB1 to SB9, the SM1 to SM10, the S11 to S13, the S14 and the point score.
Tricky cases
Can a swimmer be S7 and SB6?
Yes. The classes are set separately.
A swimmer moves to a more limited class during a meeting. Do earlier medals stand?
Yes, and their times count in the new class.
How is SM worked out for S5 and above?
Three times S plus SB, divided by four.
What is CNC?
Classification not completed: the swimmer cannot compete until it is.
Why the rule exists
Breaststroke uses the legs differently from the other strokes, so it has its own class. Medley mixes both, so its class blends the two.
Where it differs
| Where | What changes | Source |
|---|---|---|
| Physical | Separate S and SB classes | CR |
| Vision | One class for all strokes | CR A2 |
| Intellectual | S/SB/SM14 | CR A3 |
From the rule book
World Para Swimming, Classification Rules and Regulations, August 2022, with World Para Swimming, Rules and Regulations, February 2026, section 10.14. Checked 14 October 2026. Official document: the World Para Swimming Rules and Regulations, February 2026.