I recently purchased a new smartwatch, which also helps me to record my swim times.
One of the metrics that my new smartwatch records is “SWOLF”. This sounds very technical and fancy, but what exactly is this swimming SWOLF metric and how can we use it to progress our swimming?
Swimming SWOLF is a measurement of your swimming efficiency. It is calculated by adding the time you take to swim one length of the pool (in seconds) and then dividing that number by the number of strokes you take to swim that length.
I love recording my swim times and looking at data from my swim sessions. There is something really motivating about seeing your distance or times, especially if they are improving.
For me, swimming SWOLF is very exciting as I now have another metric to track and as someone who is obsessed with improving swimming technique, I really feel this is a metric worth tracking.
In this article I will cover:
- What is swimming SWOLF?
- How is SWOLF calculated?
- How can I measure my swimming SWOLF?
- What is a good SWOLF score in swimming?
- Is SWOLF useful?
What Is Swimming SWOLF?
SWOLF is a combination of the words “Swimming” and “Golf” and is a metric used to measure your swimming efficiency.
In a game of golf, the fewer swings it takes for you to put a ball in a hole, the better. This is a good golfer.
In swimming, the fewer strokes you take to swim a length of a pool without reducing your swim speed, the better. This shows you have an efficient swimming style.
So SWOLF measures how long and how many strokes you take to swim a length of the pool.
From this recorded data, a SWOLF score is calculated.
How Is SWOLF Calculated?
To calculate SWOLF, you add the time it takes you to swim one length of the pool (in seconds) to the number of strokes it took you to swim that length.
SWOLF = Time To Swim One Length [seconds] + Number Of Strokes Per Length
A stroke is counted as every time your arm is doing a pull.
For example, if you swim a 25m length in 30 seconds and take 25 strokes, you would have a SWOLF score of 55.
SWOLF = 30secs + 25 pull strokes
SWOLF Score = 55
Your target to improve your SWOLF score is to:
- Reduce how long it takes you to swim one length
- Reduce how many strokes you take over one length
- Or both
How Is SWOLF Calculated In A 20m Or 50m Pool?
SWOLF is based on swimming 25m lengths.
If you are using a smartwatch to measure SWOLF, you can tell your watch the length of the pool you are swimming in and it will work out your SWOLF score.
If you are manually working out your SWOLF score based on the formula mentioned above, but not swimming in a 25m pool, you will need to normalise your score for a 25m pool as follows:
SWOLF = (Time To Swim One Length [seconds] + Number Of Strokes Per Length) x (25/Pool Length)
For example, if you are swimming in a 50m pool and you swim one length in 60 seconds and take 50 strokes, you would still have a SWOLF score of 55.
SWOLF = (60+50)x(25/50) = 55
Keeping the universal SWOLF calculations linked to a standard pool length of 25m allows you to compare your SWOLF score no matter what length pool you are swimming in.
How Can I Measure My Swimming SWOLF?
There are two fundamental ways to measure your swimming SWOLF:
- Manually count your strokes and use the SWOLF formula to calculate your score
- Use a smart watch
How To Manually Measure Your Swimming SWOLF?
When you next swim, record the following data:
- PL – Pool Length – The length of the pool in meters.
- T – Time – The time it takes you to swim one length in seconds.
- SR – Stroke rate – How many strokes you take to swim one length.
If the pool is a standard 25m pool, you can enter the data into the following formula and manually calculate your SWOLF score:
SWOLF = T + SR
If the pool length is not 25m, use the following formula:
SWOLF = (T+SR) x (25/PL)
How To Measure Swimming SWOLF With A Smart Watch?
I always thought that swimming SWOLF was only found on the most expensive of smartwatches, but that is no longer true.
I recently purchased a smartwatch for just £24.99, which records SWOLF.
Using a smartwatch is a great way to measure SWOLF as:
- It does all the calculations for you, just presenting you with a single number.
- It will average your SWOLF over your workout, so your SWOLF score is more representative of your total swimming time and not one good length.
There is a lot of debate about how accurate fitness trackers and smartwatches actually are.
You will find big variation between different brands and more expensive does not necessarily mean better.
Personally, I like to look at my SWOLF as a benchmark. There is little point in comparing our SWOLF scores with others, but if you can reduce your SWOLF from the last time you swam, then you know you are getting more efficient as a swimmer.
What Is A Good SWOLF Score In Swimming?
There is a lot of debate about what is a good SWOLF score and if it should be used to compare ourselves to others.
Many argue (myself included) that as we are all so different in shape and size, there is little point in trying to compare our swim techniques.
On the other hand, trying to reduce your SWOLF score, whatever it is, is a great way to track your individual progress, as a lower SWOLF score means you are either swimming faster or taking fewer swim strokes since your last session.
Swimmers are a competitive group, and although I cannot find a definitive chart to tell you what SWOLF you should aim for, I have combined what other swim coaches recommend as a good SWOLF.
The following table is a guide only, to put your swimming SWOLF into context.
| Pool Length | SWOLF Score | Comments |
| 25m | 35 – 40 | Excellent |
| 25m | 40 – 45 | Very Good |
| 25m | 45 – 50 | Good |
Is A SWOLF Score Useful?
There is no one-size-fits-all answer to this question, as the usefulness of SWOLF will vary depending on your swimming ability and goals.
However, generally speaking, SWOLF can be a useful tool for measuring your swimming efficiency and helping you to improve your swimming technique.
Final Thoughts
Using a SWOLF score to measure your swimming efficiency is a great way to track your progress and see how you’re improving.
There are a few different ways to do this, including using a SWOLF calculator, stopwatch or timer, or swimming app or watch.
By tracking your SWOLF score, you can focus on the areas where you need the most improvement and make significant progress in your swimming.
Happy swimming!