SCM and LCM: short course and long course metres
Canadian swimmers race in two pool lengths, and a time is always tied to the course it was swum in.
Last reviewed . Official sources can change after that date, so open each one before relying on it.
Key answer
SCM (short course metres) is a 25 m pool and LCM (long course metres) is a 50 m pool. The same swimmer's times are not interchangeable between them for qualification; whether a time from the other course counts, and how, is set by the meet package or governing body.
The two pool lengths
- SCM, short course metres. Races in a 25 m pool.
- LCM, long course metres. Races in a 50 m pool, the length used at the Olympic Games.
Every official time is recorded with the course it was swum in, and standards are published separately for each course.
Why times differ between courses
A short course race has twice as many turns as the same distance in long course. Each turn and push-off is usually faster than open swimming, so most swimmers are faster in short course. How much faster varies by swimmer, stroke and distance, which is why any fixed adjustment is only an estimate.
Conversions and qualification
Some meets accept a time from the other course, sometimes after converting it with a method they name; others accept only one course. Whether a conversion is allowed, and how it is done, is controlled by the meet package or governing body.
An estimated conversion from a chart or calculator does not prove that a swimmer has qualified. For entry, only the method the meet package or governing body names counts.
Official sources
Official reference page
Swimming Canada: Time Standards and Preliminary Competition Information
Swimming Canada's index of national time standards and preliminary competition information. It decides which standards document is the current one.
- Publisher
- Swimming Canada
- Status
- Official reference page
- Last reviewed
- 7 October 2026
- Link
- Page on swimming.ca
Official reference page
Swimming Canada: Swimming Canada rules
Swimming Canada's published rules and policies for competition. A meet package can add conditions for its own competition.
- Publisher
- Swimming Canada
- Status
- Official reference page
- Last reviewed
- 7 October 2026
- Link
- Page on swimming.ca
More from the Canadian swimming guide
Swim Sonar is independent. It is not Swimming Canada, a provincial swimming organization or a meet host, and it does not speak for them. Official organization and meet documents control: where this guide and an official document differ, follow the official document.