Cumulative readings
01:38.5, 03:20.5, 04:57.3, and 06:37.5 become individual laps of 98.5, 102.0, 96.8, and 100.2 seconds. The third lap is fastest.
Compare splits and pace
Use MM:SS.sss, HH:MM:SS.sss, or seconds with s. Cumulative times must strictly increase.
Lap summary
Total · 1.600 km
00:06:37.50
Fastest00:01:36.80
Slowest00:01:42.00
Average lap00:01:39.38
Average pace00:04:08.44 / km
Every lap uses the same entered distance. Unit selection labels that distance; it does not convert the number.
Split comparison
| Lap | Split | Relative duration | Pace / km | km/h |
|---|---|---|---|---|
| 1 | 00:01:38.50 | 00:04:06.25 | 14.62 | |
| 2 | 00:01:42.00 | 00:04:15.00 | 14.12 | |
| 3 · fastest | 00:01:36.80 | 00:04:02.00 | 14.88 | |
| 4 | 00:01:40.20 | 00:04:10.50 | 14.37 |
Inputs and results are processed in this browser. This tool does not upload your entries or retain them after a page refresh.
How to use the Lap Time Calculator
- 01
Choose individual durations or cumulative timestamps before entering one time per line.
- 02
Set the distance traveled in each lap and label it kilometers or miles.
- 03
Review the split bars and summary, then copy or download the analysis table.
Examples
Equal-distance pace
A 96-second lap of 0.4 kilometers corresponds to 240 seconds per kilometer, or 04:00 per kilometer, and a speed of 15 km/h.
Splits versus cumulative timestamps
An individual split describes one lap. A cumulative timestamp describes total elapsed time since the start. In cumulative mode, the previous timestamp is subtracted from the next; repeated or decreasing timestamps are rejected.
Pace and speed formulas
Pace is elapsed lap time divided by distance, expressed as duration per kilometer or mile. Speed is distance divided by elapsed hours. Average pace uses total time divided by total distance, rather than an unweighted average of speed values.
Compare like with like
All laps use the same entered distance, which makes the fastest split also the fastest pace. The horizontal bar shows relative duration: a shorter bar means a quicker lap. Tied fastest splits all receive the fastest label.
What to know
- 1–500 positive lap times; total elapsed time is capped at 36,500 days.
- Pace assumes equal accurate distances and excludes GPS, elevation, and course adjustments.
Common questions
Can laps have different distances?
No. This calculator assumes equal distances. For unequal segments, calculate their paces separately or use a spreadsheet.
Does changing miles to kilometers convert the distance?
No. The selector labels the number you entered. Enter the appropriate distance when you change the unit.
Can I paste stopwatch export rows?
Paste only one duration or timestamp per line, without the CSV headers or lap numbers. The online stopwatch export can be opened separately to retrieve its cumulative values.