Short course metres — SCM
25 m
A 25 m pool, the standard for training and for most winter-season meets across Europe. Your swimmer's first championship times are usually set here.
Free tools
Swim time converter
Type a time, pick the event, and read it in the other two courses at once. It updates as you type.
Converted times
Short course (25 m)
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Long course (50 m)
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Yards (25 yd)
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Enter a time to see it converted.
The method
How the conversion works
This tool uses the factor model most of the sport has settled on — the same one built into Colorado Time Systems' software and the big team platforms. A yards time is multiplied by 1.11 to become a short course metres time. Turning a short course time into a long course one then adds a small turn allowance for every 50 m of the race, because a 25 m pool gives a swimmer twice as many walls to push off.
So a 1:10.00 over 100 m freestyle in a 25 m pool converts to 1:11.60 in a 50 m pool — same swim, two fewer turns. Three freestyle events swap distance as well as course: the 500, 1000 and 1650 yd races convert to the 400, 800 and 1500 m, the nearest equivalent races on the programme rather than the same event.
| Stroke | Seconds per 50 m |
|---|---|
| Butterfly | 0.70 |
| Backstroke | 0.60 |
| Breaststroke | 1.00 |
| Freestyle | 0.80 |
| Medley | 0.80 |
| Event | Multiplier |
|---|---|
| All other events | × 1.11 |
| 400 m ↔ 500 yd freestyle | × 0.8925 |
| 800 m ↔ 1000 yd freestyle | × 0.8925 |
| 1500 m ↔ 1650 yd freestyle | × 1.02 |
Pool lengths
The three courses
Long course metres — LCM
50 m
The 50 m Olympic pool. Championship season generally moves long course in spring and summer, and everyone's times get slower — that's the pool, not the swimmer.
Short course yards — SCY
25 yd = 22.86 m
The 25 yd pool used by American schools and universities. It matters mostly when a swimmer starts comparing times with US college programmes.
Reading the result
What a converted time is for
Converted times answer everyday questions: whether a short course best is inside a qualifying time published in long course, how the winter season compares with the summer one, or what a 100 free from Sintra would look like on an American recruiting page.
Treat the output as a well-informed estimate, not a promise. The factors were fitted to millions of age-group races and assume average turns for the stroke. A swimmer with strong underwater work usually beats the converted long course prediction; one still learning turns usually comes in behind it. And meet organisers have the final say on whether converted entry times are accepted — the meet announcement will tell you.
Questions
Common questions
Why are short course times faster than long course?
Turns. Every wall is a push-off, and a push-off is faster than swimming. In a 25 m pool a 100 m race has three turns; in a 50 m pool it has one. More walls, more free speed — usually one to two seconds per 100 m.
How accurate are converted times?
For most age-group swims they land within about a second per 100 m of the real thing. The factors describe an average swimmer, so individual turn skill, underwater kick, and even age move the result. Converted times are for comparison, not prediction.
Are converted times accepted for meet entries?
Sometimes. Some meets accept entries converted from another course, others require times swum in the meet's course. The meet announcement — or your club's coach — is the authority. When in doubt, ask before entering.
What do SCM, LCM and SCY stand for?
Short course metres (25 m pool), long course metres (50 m pool) and short course yards (25 yd pool). Europe races the first two; yards belong to American school and college swimming.
Why does the 400 m freestyle convert to a 500 yd time?
Yards pools run different distance events. The 500, 1000 and 1650 yd freestyles are the closest equivalents to the 400, 800 and 1500 m, so the standard factors convert between those pairs rather than pretending the distances match.
Do the conversions work for elite senior swimmers?
Less well. The factors were fitted to age-group racing, and senior internationals tend to out-swim them, most obviously in the distance events. For a twelve-year-old's meet planning they're usually close enough; for a national finalist, coaches lean on real times in each course.
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