Swim pace calculator
Choose an event, model how the pace changes, and see every split reconcile to your exact finish time—for pool or open water.
Plan your swim
Event setup
Results and the chart update instantly.
Freestyle · 400m
Negative split pacing plan
Average pace
1:30.0- Opening pace
- 1:31.8/100
- Closing pace
- 1:28.2/100
- Average speed
- 1.11 m/s
Pace profile
Faster pace appears higher. Every split reconciles to the exact finish.
The second half is 4% faster than the first. This protects the opening effort and creates a decisive finish.
What the curve means
The second half is 4% faster than the first. This protects the opening effort and creates a decisive finish.
- 25m
- 0:23
- 200m
- 3:04
- 400m
- 6:00
| Segment | Segment time | Pace /100 | Elapsed |
|---|---|---|---|
| 0–25m | 0:22.9 | 1:31.8 | 0:23 |
| 25–50m | 0:22.9 | 1:31.8 | 0:46 |
| 50–75m | 0:22.9 | 1:31.8 | 1:09 |
| 75–100m | 0:22.9 | 1:31.8 | 1:32 |
| 100–125m | 0:22.9 | 1:31.8 | 1:55 |
| 125–150m | 0:22.9 | 1:31.8 | 2:18 |
| 150–175m | 0:22.9 | 1:31.8 | 2:41 |
| 175–200m | 0:22.9 | 1:31.8 | 3:04 |
| 200–225m | 0:22.0 | 1:28.2 | 3:26 |
| 225–250m | 0:22.0 | 1:28.2 | 3:48 |
| 250–275m | 0:22.0 | 1:28.2 | 4:10 |
| 275–300m | 0:22.0 | 1:28.2 | 4:32 |
| 300–325m | 0:22.0 | 1:28.2 | 4:54 |
| 325–350m | 0:22.0 | 1:28.2 | 5:16 |
| 350–375m | 0:22.0 | 1:28.2 | 5:38 |
| 375–400m | 0:22.0 | 1:28.2 | 6:00 |
Training targets
Turn one swim into useful training targets.
Pace is more than a finish-time statistic. It helps you choose realistic intervals, understand whether the opening part of a swim was sustainable, and plan rest before the next repeat.
Use the calculator after a time trial, before a pool session, or whenever a workout gives you a target that needs translating into 25, 50, or 100 splits.
How to use the swim pace calculator
Three inputs are enough to turn a goal or completed swim into pool-ready numbers.
- 01
Choose what you know
Start with a completed swim and total time, a target pace, or the pace and rest you want for a repeat set.
- 02
Choose the event and strategy
Select the stroke, race distance, course, and an even, negative, fast-start, or progressive pace profile.
- 03
Use the targets in training
Copy the result, plan your splits and send-offs, or turn the targets into a structured Swimio workout.
The calculation
How swimming pace is calculated
Convert the total time to seconds, divide it by the distance, then multiply by 100. A 25-minute 1,500-metre swim is 1,500 seconds ÷ 1,500 × 100 = 100 seconds, or 1:40 per 100 metres.
When you select a pacing strategy, Swimio weights each segment, then normalizes the curve back to the exact target time. The opening, closing, and cumulative splits therefore remain mathematically consistent.
- Pace
- The time required to swim a standard distance—usually 100 metres or 100 yards.
- Split
- The projected or recorded time at an intermediate distance within the swim.
- Send-off
- Swimming time plus planned rest, measured from the start of one repeat to the start of the next.
Pool courses and open water explained
Choose the course you actually swim. The calculator keeps results in that course’s unit instead of applying a one-size-fits-all performance conversion.
SCY
Short Course Yards: a 25-yard pool, common in the United States.
SCM
Short Course Metres: a 25-metre pool, common for training and short-course racing.
LCM
Long Course Metres: a 50-metre pool used for Olympic and long-course competition.
Open water
Standard 500-metre through 25-kilometre events, plus any custom distance in metres.
Swim pace calculator questions
How do I calculate my swim pace per 100?
Divide your total swim time in seconds by the distance, then multiply by 100. For example, 1,500 metres in 25 minutes is 1 minute 40 seconds per 100 metres. Swimio performs the calculation and shows useful 25, 50, and 100 splits automatically.
What is a swimming send-off?
A send-off is the fixed interval between the start of one repeat and the start of the next. If you swim 100 metres in 1:40 and want 15 seconds of rest, your send-off is 1:55.
What is the difference between swim pace and send-off time?
Pace describes how long you take to swim a distance. Send-off includes both the expected swimming time and the planned rest before the next repeat starts.
Does the calculator work for yards and metres?
Yes. Select SCY for a 25-yard pool, SCM for a 25-metre pool, LCM for a 50-metre pool, or open water in metres. Results stay in the selected unit, so the calculator does not imply an inaccurate performance conversion between yards and metres.
How does the pace strategy chart work?
Choose even, negative split, fast start, or progressive pacing. Swimio distributes the effort across practical checkpoints, then normalizes every split so the cumulative plan still equals your exact target finish time.
Is the Swimio pace calculator free?
Yes. The calculator is free, requires no account, and displays results immediately. Swimio is optional if you want to turn the targets into a structured workout and follow it on Apple Watch.
Take it to the pool
From calculated pace to guided workout
Build structured sets in Swimio and follow pace, rest, and live guidance on Apple Watch.