How do I use the TCX and GPX files?

After downloading, import the TCX file to Garmin Connect or your Garmin watch. GPX files can be uploaded to Strava, Wahoo, or other fitness apps. These files contain your custom pacing strategy for each kilometer or mile.

Free Negative Split Calculator

Calculate progressive negative split pacing plans for your next race. Perfect for 5K, 10K, half marathon, and marathon distances. Generate custom splits where each segment gets progressively faster. Download FIT workout files for Garmin watches and other fitness apps.

Calculate Your Pacing Strategy

per kmper mile

Race distance

Custom distance (km)

Hours

Minutes

Seconds

Negative split percentage5.0%

5% faster average pace in the second half vs the first half.

Progressive pacing breakdown showing segment distance, pace, and cumulative times
#	Seg (km)	Pace (/ km)	Seg time	Cum km	Cum time
1	1.000	4:36	4:36	1.000	4:36
2	1.000	4:35	4:35	2.000	9:12
3	1.000	4:33	4:33	3.000	13:46
4	1.000	4:32	4:32	4.000	18:18
5	1.000	4:30	4:30	5.000	22:49
6	1.000	4:29	4:29	6.000	27:18
7	1.000	4:27	4:27	7.000	31:46
8	1.000	4:26	4:26	8.000	36:12
9	1.000	4:24	4:24	9.000	40:36
10	1.000	4:23	4:23	10.000	44:59

Average pace first half vs second half honours your 5% negative split by construction.

Sign in to Download Workouts

Connect with your favorite fitness platform to download FIT workout files

Frequently Asked Questions

What is a negative split in running?

A negative split is a pacing strategy where you run the second half of your race faster than the first half. Our calculator creates progressive splits where each segment gets progressively faster, helping you finish strong.

How do I use the FIT files?

After downloading, import the FIT file to Garmin Connect or your Garmin watch. FIT files are the native workout format for Garmin devices and contain your custom pacing strategy with structured workout steps for each kilometer or mile.

What distances can I calculate splits for?

We support all major race distances: 5K, 10K, 15K, half marathon (21.1km), marathon (42.2km), 50K, and 100K. You can also enter custom distances for ultra marathons or other events.

Is this calculator free to use?

Yes! The negative split calculator is completely free. You only need to sign in with Google, Facebook, Apple, Strava, or Garmin to download the workout files.

What's the difference between km and mile pacing?

Toggle the switch to calculate your splits per kilometer or per mile. The calculator automatically converts distances and shows your target pace for each segment in your preferred unit.