Health⏱ 5 min read
How to Calculate Your Swimming Pace and Improve Your Times
Swimming pace is measured differently from running — per 100m instead of per km. Here's how to calculate it, what good times look like for each stroke, and how to use pace to structure your training.
Swimming pace is the most fundamental metric in pool training, yet many recreational swimmers never track it. Once you understand pace per 100m, you can benchmark your fitness, set realistic goals, and structure your sessions with purpose.
How Swimming Pace Is Measured
Unlike running (pace per km) or cycling (speed in km/h), swimming uses pace per 100 metres as the standard unit. A 50m pool is the standard; a 25m pool (short course) typically produces slightly faster times due to more turns.
Pace per 100m = Total time ÷ (Distance in metres ÷ 100)
Example: Swimming 400m in 8 minutes 20 seconds (500 seconds)
Pace = 500 ÷ (400 ÷ 100) = 500 ÷ 4 = 125 seconds per 100m
= 2 minutes 05 seconds per 100m
Reference Times for Freestyle (Front Crawl)
Level100m Pace1,500m Time
Beginner (continuous)2:30–3:00 /100m~37–45 min
Recreational / club1:45–2:15 /100m~26–34 min
Competitive age-group1:20–1:45 /100m~20–26 min
Masters (trained adult)1:05–1:20 /100m~16–20 min
Elite amateurBelow 1:05 /100mBelow 16 min
Using Pace for Interval Training
The most effective way to improve swimming fitness is interval training — repeated swims at a target pace with measured rest. The key concept is the interval send-off: the total time between the start of one repeat and the start of the next.
Example: 10 × 100m on a 2:00 send-off
• Start 100m at 2:00 pace clock
• Finish in 1:40 → 20 seconds rest
• Start again when clock hits 2:00
• Finish in 1:42 → 18 seconds rest
As you get fitter, you can cut send-off time:
10 × 100m on 1:55 → less rest, more aerobic stress
CSS Pace: The Swimmer's Threshold
Critical Swim Speed (CSS) is the swimming equivalent of lactate threshold pace — the fastest pace you can sustain aerobically. It's calculated from two time trials:
CSS pace = (400m time − 200m time) ÷ 2
Example:
400m time trial: 7:30 (450 seconds)
200m time trial: 3:30 (210 seconds)
CSS = (450 − 210) ÷ 2 = 120 seconds per 100m = 2:00 /100m
Train at CSS for threshold sets; slightly slower for aerobic base work.
Converting Between Pool Lengths
Short course (25m pool) pace is typically 3–5 seconds per 100m faster
than long course (50m pool) for the same swimmer.
Long course equivalent ≈ Short course time + (3–5 sec per 100m)
This matters when comparing times or training across pool types.
Drills That Actually Improve Pace
Raw fitness helps, but technique improvements often produce bigger pace gains for recreational swimmers. The highest-leverage drills:
- Catch-up drill: One hand stays extended while the other completes the pull, enforcing a longer glide and better catch position
- Fist swimming: Closing fists removes paddle surface, forcing engagement of the forearm in the catch — you feel the difference immediately when you reopen your hands
- Single-arm freestyle: Isolates the catch and pull mechanics on one side at a time
- Counting strokes: Lower stroke count per length (with the same or faster pace) indicates improved efficiency