A split table converts one goal — say, 5 km in 25:00 — into a checklist of times you can actually watch for during a race. Every row answers two questions: what should the clock read at this point (cumulative), and how long did the piece since the last point take (segment).
The two time columns
The cumulative column grows from zero to your target time. It is the number you compare against your watch as you cross each marker. The segment column resets every row; it tells you how fast that stretch was, which is what you actually control stride by stride.
In an even-split table built by the race split calculator, segments are identical by construction when the interval divides the distance evenly. The 5 km in 25:00 example with 1 km intervals shows 5:00 in every segment row and cumulatives of 5:00, 10:00, 15:00, 20:00 and 25:00.
The finish row and partial segments
When your interval does not divide the race distance evenly, the last row covers a shorter piece. A 5 km race with 1-mile intervals has three full miles (4828.032 m) plus a residual of 171.968 meters, so the table shows four rows: cumulatives of 8:03, 16:06 and 24:08, then the finish at 25:00 with a short 0:52 segment. The finish row always carries the exact residual distance in meters so you can see how short the final piece is.
Why a 1-second wobble is normal
Internally the calculator keeps exact times: cumulative at each boundary is target × boundary distance ÷ race distance, never rounded. Only for display are cumulatives rounded to the whole second, and each displayed segment is the difference between two rounded cumulatives. That guarantees displayed segments sum exactly to your finish time — the arithmetic stays honest — but it can make two identical-effort miles differ by a second, like the 8:03, 8:03, 8:02 sequence in the example above. Nothing about your pacing changed; the clock display just snapped to whole seconds.
Using the table during a race
Print the table (the print layout keeps the brand header, your assumptions and the method note), attach it to a race band, and check the cumulative column at each marker. If you are consistently ahead of or behind the cumulative times, you have a facts-first record of it afterward — which is the honest input for planning the next race, not a verdict on the current one.