Quick answer
To convert a long course (LCM) time to short course yards (SCY), multiply by about 0.88 for a 50, 100 or 200 (a 1:05.00 in the 100 LCM is about 57.39 SCY). To go from SCY to LCM, divide by the same number. Type any time in the free converter below and it does the math for every stroke and distance, no sign-up needed.
Free tool
Convert a swim time between pools
Same conversion factors the Gophin app uses. Conversions are estimates: turns and underwater skill change the real gap for each swimmer.
That is the whole answer for most parents: pick the stroke, the pool your swimmer raced in, the event and the time, and read the other two pools. The rest of this page explains where the numbers come from, why a converted time can be off for your swimmer, and how to stop converting times one by one.
What the three pools are
- SCY (short course yards): a 25-yard pool. US club swimming in the fall and winter, high school and college (NCAA).
- SCM (short course meters): a 25-meter pool. The winter season in Canada, Europe and most of the world.
- LCM (long course meters): a 50-meter pool, the Olympic pool. Summer season, national championships, Olympic Trials, World Championships.
The same event name hides different races. A "100 free" in yards is 100 yards (91.44 m). In a 25-meter pool it has three turns; in a 50-meter pool it has one. If you want the longer version of this, read what SCY, SCM and LCM mean.
How the conversion works, in plain words
The converter does two separate adjustments.
1. Yards to meters (SCY ↔ SCM). Both pools are 25 long, so the number of turns is the same. Only the distance changes: 100 yards is shorter than 100 meters. For the 50, 100 and 200 of every stroke, and for the 400 IM, an SCY time is multiplied by 1.11 to get the SCM time.
The freestyle distance events are not swum at the same distance in both pools, so they have their own factors:
| Yards event | Meters event | SCY → SCM factor |
|---|---|---|
| 500 yd free | 400 m free | × 0.8925 |
| 1000 yd free | 800 m free | × 0.8925 |
| 1650 yd free | 1500 m free | × 0.98 |
2. Short course to long course (SCM ↔ LCM). Same distance, fewer walls. Every push-off is a free burst of speed, so a 50-meter pool is slower. The longer the race, the more walls a swimmer loses, so the gap grows with distance:
| Distance | SCM → LCM | What it means |
|---|---|---|
| 50 | ÷ 0.985 | LCM about 1.5% slower |
| 100 | ÷ 0.98 | LCM about 2% slower |
| 200 | ÷ 0.975 | LCM about 2.5% slower |
| 400 | ÷ 0.97 | LCM about 3% slower |
| 800 | ÷ 0.965 | LCM about 3.5% slower |
| 1500 | ÷ 0.96 | LCM about 4% slower |
LCM to SCY chains both steps. For a 100: LCM × 0.98 ÷ 1.11, which is the "× 0.88" shortcut in the quick answer. For a 50 the shortcut is × 0.887, for a 200 it is × 0.878.
A worked example with a real-looking age group time: a 1:05.00 in the 100 free LCM.
- LCM → SCM: 65.00 × 0.98 = 63.70, so 1:03.70 SCM
- SCM → SCY: 63.70 ÷ 1.11 = 57.39, so 57.39 SCY
Notice that the factors change with distance, not with stroke: a 100 back and a 100 free convert with the same numbers.
Want the answer without typing? The LCM to SCY conversion chart lists ready-made conversions for every distance.
When a converted time is wrong for your swimmer
A conversion is an average. It tells you what is roughly equivalent, not what your swimmer will swim. It misses in predictable ways:
- Great turns and underwaters. A swimmer with strong dolphin kicks gains more from every wall than the average swimmer. Their short course times are "better" than their long course times, so converting SCY to LCM will flatter them. Backstrokers and butterflyers with long underwaters are the usual case.
- Weak turns, strong stroke. The opposite: they lose less going to a 50-meter pool, and their real LCM time can beat the conversion.
- Distance events. Pacing a 1500 in a 50-meter pool is a different skill from a 1650 in a 25-yard pool. Distance swimmers who pace well in one pool are not always as strong in the other.
- Young swimmers. A 10-year-old's turns change month to month. Convert, but compare against their own history in the same pool first.
- Not a legal time. A converted time cannot be entered as a meet entry time unless the meet says so. Most meets want a time swum in the pool the standard is written for.
The honest way to use a conversion: to set a first goal for a new season, to read a standard written in the other pool, or to understand a swimmer who moved from Canada to the US (or back).
Stop converting times one by one
The calculator above is perfect for one time. When you follow a swimmer all season, you end up doing it for every event after every meet.
In Gophin, you pick a pool on your swimmer's best times and every personal best appears converted next to the time they actually swam, marked with "≈" so you never confuse a real swim with an estimate. The comparison with time standards uses those conversions too, so a summer swimmer can see how close they are to a winter SCY cut. Results come in from official meets on their own; you do not type anything.
See your swimmer's times in every pool (free)
Common conversions parents ask about
Canadian winter season to US college (SCM → SCY). Divide the SCM time by 1.11 for the 50, 100, 200 and 400 IM. A 58.00 in the 100 free SCM is about 52.25 SCY. For the 400 free, divide by 0.8925 to get a 500 yd estimate.
Summer long course to next winter's yards goals (LCM → SCY). Use the chart or the calculator. A 2:20.00 in the 200 free LCM is about 2:02.97 SCY.
US yards times to a long course standard (SCY → LCM). A 25.00 in the 50 free SCY is about 28.17 LCM. That is the question behind most "scy to lcm" searches: can my swimmer make a summer cut?
SCM to LCM. Divide by the distance factor above. A 1:10.00 in the 100 breast SCM is about 1:11.43 LCM.
Bottom line
Use the calculator for a quick answer, the chart when you want to scan, and keep the real swims separate by pool. When you get tired of converting by hand, let Gophin do it for every best time at once.
To see how close a converted time is to a real cut, open Compare → Standards in Gophin: it uses these conversions so a summer swimmer can see the gap to a winter SCY standard. Free.
Source: Gophin's conversion factors, the ones the calculator on this page runs. National federations and meets sometimes publish their own conversion tables for entry purposes; when a meet announces an official conversion, that one wins.
