Why are short-course times faster?

A 25m pool has twice as many turns per distance as a 50m pool, and a good push-off underwater is faster than swimming on the surface. Those extra turns make short-course times measurably quicker, which is why a conversion is needed to compare fairly.

How much faster is short course?

The gap depends on stroke and distance. Sprints gain proportionally more from turns, and breaststroke and butterfly benefit most because their underwater phases are efficient. Typical differences range from roughly 1% for a 50m freestyle to 3% or more for distance and form-stroke events.

Is this exactly the FINA points conversion?

No single percentage matches FINA's full points system, which uses base times per event. This tool uses event-specific percentage adjustments calibrated to the typical short-course advantage, so it is a close practical estimate rather than an official points conversion.

Which direction does it convert?

Both. Tell the tool whether your time was swum in a 25m or 50m pool and it converts to the other. Converting short course to long course adds time (removes the turn advantage); long to short removes time.

Can I use this for yards pools?

This calculator handles metric 25m and 50m courses only. A 25-yard pool is shorter than 25 metres, so yard times need a separate distance-based conversion before any course adjustment, which this tool does not perform.

What is the Swimming Short-Course to Long-Course Converter?

Enter a swim time set in a 25m short course or 50m long course pool to get the estimated equivalent in the other pool length, using event-specific turn-advantage adjustments per distance and stroke. It runs free in your browser on Gera Tools, with nothing uploaded.

Swimming Short-Course to Long-Course Converter

Name: Swimming Short-Course to Long-Course Converter
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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Compare 25m and 50m times fairly

A time swum in a 25m pool is not directly comparable to one swum in a 50m pool, because the shorter course gives you twice as many fast turns. To rank a swim or set a realistic target you must convert between short course (SCM) and long course (LCM). This tool applies an event-specific adjustment so you can move a time from one course to the other.

Why short course is faster

In a 25m pool you touch the wall twice per 50m of swimming, while in a 50m pool you touch once. Each touch gives you:

A push-off at a velocity well above race pace.
An underwater streamline phase (dolphin kicks for fly, back, and free; breaststroke pull-down for breast) that is hydrodynamically faster than swimming on the surface.

These advantages compound over longer distances: a 200m swim in a 25m pool has 7 turns versus 3 in a 50m pool. Breaststroke gains the most because the legal pull-down is particularly efficient. Freestyle in a sprint gains the least proportionally.

How it works

Short course is faster by a percentage that depends on stroke and distance — more turns and more efficient underwater phases mean a bigger advantage. The tool stores a turn-advantage percentage per event, then:

long_course_time  = short_course_time × (1 + advantage)
short_course_time = long_course_time  ÷ (1 + advantage)

Sample advantages used (fraction of total time saved in short course vs long course):

Event	Approximate SCM advantage
50m freestyle	~1.0%
100m freestyle	~1.6%
200m freestyle	~2.0%
400m freestyle	~2.5%
100m backstroke	~1.8%
100m butterfly	~1.7%
100m breaststroke	~2.2%
200m breaststroke	~3.0%

Worked example

A 100m freestyle of 54.20 in a 25m pool, with a 1.6% advantage:

Long-course equivalent = 54.20 × 1.016 ≈ 55.07

Going the other way, a 55.07 long-course time converts to:

Short-course equivalent = 55.07 ÷ 1.016 ≈ 54.20

Practical uses for this tool

Comparing recruits across venues. A club that trains in a 25m pool can compare their swimmers fairly with a rival who trains in a 50m venue for open meets.
Setting long-course targets. If your 100m freestyle personal best is 54.20 in short course, your equivalent long-course target is approximately 55.07.
Selecting events for competitions. Swimmers with strong underwater dolphin kicks gain more from short course and may prioritise those meets for personal bests.

Treat the result as a planning estimate: individual turn quality can move the real gap by several tenths. Verify against your own season-best comparisons where you have both course times. This tool handles metric pools (SCM 25m and LCM 50m) only — it does not convert to or from yards.