How Many Swimming Laps are in One Mile?

May 19, 2024

Table of Contents

How many lengths of a swimming pool is a mile? Swimming a mile is, well, a milestone! But how many laps are in a mile, anyway? The answer to that depends on two things: how you define a mile and the length of your pool.

Use Our Calculations and Get Back to Training

The overly-simple answer is this:

  • To swim 1650 yards in a pool measuring 25 yards you would need to do 66 lengths of the pool
  • In a pool measuring 50 yards you would need to do 33 lengths.
  • You can use the same calculation for a 25 meter pool (66 lengths to swim 1650 meters, or 33 length of a 50 meter pool)
Definition of a mile
(in yards or meters)
# of laps of a 25 yard or 25
meter pool in one mile
# of laps of a 50 yard or 50
meter pool in one mile
1500 60 30
1650 66 33
1760 70.4 35.2

In short, you divide one mile by the length of your pool. But, as usual, the devil is in the details. Let’s look at our equation: one mile/pool length = # of laps in a mile.

Define a "Mile”

What is a mile anyway? Ask a simple question, get a complicated answer. The definition of a mile will vary depending on who you ask. Here’s what various people will tell you.

  • Ask a scientist: Technically, a mile equals 1760 yards and 1609.3 meters.
  • Ask an open water swimmer: In open water, a mile is a mile. If your aim is to swim a mathematically-accurate mile and your pool is measured in yards, divide 1760 by the number of yards in your pool. If your pool is measured in meters, divide 1609.3 by the length. 
  • Ask a pool-swimmer about training: For training purposes, most competitive swimmers and their coaches think of a mile as 1650 meters (remember, a mile is technically 1609.3 meters). But here’s where it gets admittedly weird: competitive swimmers also tend to call 1650 yards a mile, as well. Yes, technically this is 90 yards short of a mile. 
  • Ask a pool-swimmer about a meet: In competitive swimming the “mile” event in a meet is either 1500 meters or 1650 yards, depending on whether the pool is measured in meters or yards.

If, like many people, you are swimming a mile in preparation for swimming the “mile” event in a meet, use 1650 as your mile-marker, regardless of whether your training pool is yards or meters, and you will have plenty of endurance to last until the last lap of your race. 

Pool Length

Once you have defined what you mean by “a mile” (probably 1650 meters or yards), you need to determine how long your pool is. This is about as simple as it sounds.

Most lap pools are 25 yards, 25 meters or 50 meters. Less common are 50-yard pools.

Even less common but still around are some mathematically difficult lengths: 33.3 meters, for example. Just ask an employee at your local pool what the length is or look it up in our pool locator if you are not sure.

Not sure how long your backyard pool is? Here’s an easy, not-so-technical way to measure your pool. Get a friend and a long, water-friendly tape measure. Jump in the water and put the 0-inches end of the tape against the wall at one end. Hold it there while your friend pulls the tape to the opposite end of the pool and reads what it says against the far wall.

Once you have determined how you want to measure a mile and how long your pool is you are ready to do some simple math.

Amazingly True Story

A 50-meter pool built before the invention of touch-pads is no longer 50-meters long when the touch-pads are IN the pool. Records set in so-called “short” pools cannot count as records.

Before a major international competition, meet organizers discovered this very problem. With touch-pads in the water, the pool was 1 cm short of 50 meters. With hundreds of swimmers set to arrive in a matter of days, the facility drained the pool, shaved 1cm off the wall, re-plastered the shaved surface, and re-filled the pool, with only hours to spare. The benefit of such frenzied, last-minute construction: over 100 new world records were set that week.

Do Some Math

Now that you have your definition of a mile and the length of your pool, plug your numbers into the formula below. Just make sure the units you are using are consistent. For example, if your pool is measured in yards, use a number of yards as your definition of a mile (1760 or 1650, most likely).

(Your definition of a mile) / (the length of your pool) = (# of laps you need to swim to swim a mile)

Define a "Lap”

The old-school, technically-probably-correct definition of a “lap” is two lengths of the pool: down and back. Linguistically this makes sense: when you “lap someone” you have swum two lengths of the pool to catch up to them. However, in practice, it is far more common for people to say “laps,” and mean “lengths.” In the chart, we have used the “one lap means once across the pool” definition.

Take the Easy Way Out

If you have a training watch designed for swimming you can pair it with the app to track how many laps you are swimming and in turn how far you swam.