Pace, time and distance are locked together: fix any two and the third is decided. That is why one tool answers three different questions — what pace gets me under four hours, how long will this route take at my usual pace, how far did I actually go in that hour. The arithmetic never changes; only which box you leave empty does.

Using it in three steps

1. 1 Pick a distance, or tap one of the race buttons to fill it in.
2. 2 Add either the time you want to finish in or the pace you can hold — not both.
3. 3 Read the split table. Those are the times to see on your watch at each marker.

Why runners think in pace, not speed

Speed answers "how fast", pace answers "how long until the next marker", and the second is the one you can act on mid-run. A watch showing 12.4 km/h tells you little at kilometre 30; a watch showing 4:50 per kilometre tells you exactly whether the next one is on plan. Pace is time per distance rather than distance per time, which is also why a lower number is a faster runner — the one thing about it that confuses newcomers every time.

What the split table is really for

Almost nobody runs a race at one steady pace, and the split table is not pretending otherwise. Its job is to be a reference you glance at: two seconds ahead at halfway is fine, ninety seconds ahead is a warning you can act on while there is still race left. Runners who blow up in the last quarter usually banked that time in the first, and the table is where that shows up before the legs report it.