Distance calculation has always been a confusing chapter in swimming. The true mile, that we are used to, does not apply to the competitive swimming space. To make life even more complicated, swimming pools vary in size and shape. So how can you calculate swimming laps correctly?
In an Olympic size 50-meter swimming pool, 30 laps make up 1 swimming mile considering 1 lap equals 50 meters, not a roundtrip of the pool, and 1 swimming mile equals 1500 meters, 1650 yards, or 4921 feet.
Lap Chart for 1 Swimming Mile (1500 Meters, 1650 Yards, or 4921 Feet)
| Laps (1 Lap = 50 Meters) | |
|---|---|
| 20-Yard Pool | 82.5 |
| 20-Meter Pool | 75 |
| 25-Yard Pool (Short Course) | 66 |
| 25-Meter Pool | 60 |
| 50-Meter Pool (Olympic Size) | 30 |
Swimming Mile is Not a True Mile
It is easy to confuse a swimming mile for a true mile. Even though they are the same in any distance-based sports, they are not in swimming. Why so?
A true mile is 1609 meters. In Olympics, a standard swimming pool is 50 meters in length. This creates a fraction when counting how many laps a swimmer swam. To avoid this problem, they decided to shrink the mile down to 1500 meters which have now become a standard worldwide.
| Kilometers | Meters | Yards | Feet | |
|---|---|---|---|---|
| Swimming Mile | 1.50 | 1500 | 1650 | 4921 |
| True Mile | 1.61 | 1609 | 1760 | 5280 |
The Confusion Between Laps and Lengths
If you are new to swimming, you need to get this fact straight. One lap is not one back and forth of a swimming pool unless you are swimming in a 25-meter pool.
In the swimming Olympics, one lap is equal to 50 meters which is the same as the length of their professional swimming pools. So if you are training in a 50-meter swimming pool, one lap is going from one side of the pool to the other.
However though in the United States, the standard length for a swimming pool is 25 yards. It is also the size they use for swimming competitions within the country. It raises a whole lot of confusion among people.
The simplest way to solve this would be by remembering that 1 lap equals 50 meters and doing the maths.
The length refers to the distance from one side to the other side of the pool, and a lap can be one length or two lengths of a swimming pool depending on its size. Some people therefore always recommend using the term “length” instead.
How to Calculate Laps in Open Water
Calculating laps in open water or converting pool time to open water swimming time is not any different. All of you have to know are the conversions between meters, yards, and feet.
To give you an example, if you swam 25 laps in a swimming 50-meter swimming pool (considering 1 lap = 50 meters), you have just swum 25 * 50 = 1250 meters, 1250 * 1.09 = 1362.5 yards, and 1250 * 3.2 = 4000 feet in ocean/lake water, factoring out temperature and other environmental changes.
| Meters | Yards | Feet |
|---|---|---|
| 1 | 1.09 | 3.2 |
Does the Calculation Change for Triathlons?
Triathlons generally use various forms of sports in one race and to generalize the metric for calculating distance they go back to the true mile for swimming. This means the calculations we did until this point is going to change for the triathlon.
Now that 1 mile will be 1609 meters or 1.61 km again, a half ironman would be 38 laps and an ironman would be 77 laps in a 50-meter pool where 1 lap is the distance of the pool, not the roundtrip.
| Laps (1 Lap = 50 Meters) | |
|---|---|
| Olympic Distance (1 Mile) | 30 |
| Half Ironman Distance (1.2 Miles) | 38 |
| Ironman Distance (2.4 Miles) | 77 |