Calculator
Example data table
| Event | Course | Official time | Pace per 100 | Speed | Planning note |
|---|---|---|---|---|---|
| 400 m freestyle | 50 m pool | 4:40.50 | 1:10.13 | 1.426 m/s | Solid even split baseline for aerobic race work. |
| 200 yd butterfly | 25 yd pool | 2:01.80 | 1:00.90 | 1.642 yd/s | Useful for pacing broken race rehearsal sets. |
| 1500 m freestyle | 50 m pool | 16:12.40 | 1:04.83 | 1.543 m/s | Track sustainable threshold pace and split drift. |
Formula used
Official time: minutes × 60 + seconds + hundredths ÷ 100
Swim-only time: official time − reaction time
Average pace: official time ÷ race distance × selected pace distance
Speed: race distance ÷ official time
Projected event time: average pace per unit distance × projected distance
Split strategy: even pacing uses equal half-distance pace. Negative or positive pacing shifts first-half and second-half time by the selected bias percentage.
How to use this calculator
- Enter the race distance and choose meters or yards.
- Select a course preset or type a custom pool length.
- Enter your official race time and optional reaction time.
- Choose the pace distance you want to monitor.
- Select an even, negative, or positive split strategy.
- Add a goal time to compare current pace against targets.
- Press Calculate pace to see results above the form.
- Review the split table, projected times, and Plotly graph.
- Use the CSV and PDF buttons to export a summary.
FAQs
1. What does pace per 100 show?
It shows how long you would take to cover 100 meters or yards at your current average race speed. Coaches use it to compare swims across different event distances and training sets.
2. Why is reaction time separated?
Official race time includes the start. Separating reaction time helps you estimate pure in-water speed, compare starts, and see whether pace changes came from swimming or block response.
3. When should I use negative split pacing?
Use negative splitting when you want a controlled opening and a stronger back half. It is common in middle-distance freestyle, open-water planning, and threshold training sets.
4. Can I use this for yards and meters?
Yes. The calculator supports both units and also handles a pool length that differs from the event unit by converting distances before creating lap and split targets.
5. What does split bias percent change?
It changes how much faster or slower the second half becomes relative to the first half. A small bias gives gentle pacing shifts, while a larger bias creates stronger split contrast.
6. Why do projected times matter?
Projected times help you estimate equivalent performance at other distances from the same average pace. They are useful for planning meet goals, training sets, and race strategy discussions.
7. Does this replace real split analysis?
No. It gives a strong planning model, but real races include turns, stroke changes, fatigue, traffic, and tactical choices. Use actual recorded splits whenever possible.
8. Can I use it for open water events?
Yes, but lap-based split tables are most realistic in pool races. For open water, use the pace, speed, goal comparison, and projection features as the main planning tools.