Race Pace and Finish Time Suite

A finish-time goal becomes useful only when it can be carried through the distance as realistic checkpoints. Average pace links distance and elapsed time, but race execution also depends on where effort changes, how much time is spent stopped, and how closely the evidence matches the target event.

There are three common starting points. A runner may already know the desired pace, speed, or finish time; may have a recent race result to project over another distance; or may want a rough marathon estimate from a training block. These are not interchangeable forms of evidence. Direct pace arithmetic describes the goal that was entered, while prediction models add assumptions about endurance carryover.

Moving time and elapsed time also need to stay distinct. Planned stops are part of the race clock, so adding two 30-second pauses makes the finish one minute slower even when the running pace is unchanged. A checkpoint that contains a stop will look slower than neighboring splits because the row includes both movement and pause time.

Pacing shape changes where the same adjusted moving time is spent. An even plan distributes it by distance. A controlled start or negative split gives early checkpoints more time and later checkpoints less. A late-fade scenario moves more time toward the final portion. These profiles are planning shapes, not physiological forecasts.

No formula sees hills, wind, heat, altitude, congestion, fueling, illness, injury, or whether a prior race was truly maximal. Use a precise clock as a way to compare assumptions and prepare checkpoints, not as a guarantee of race-day performance.

How to Use This Tool:

Choose the evidence path first, confirm its neutral finish, and then add pacing shape or stop time.

1. Select Planning mode. Use the direct plan for a chosen goal, recent-race prediction for a verified finish, or training estimate for a rough marathon scenario.
2. Enter the distance and the evidence required by that mode. For clock fields, use MM:SS or H:MM:SS; for custom distance, check the kilometre or mile unit.
3. Choose kilometre or mile checkpoints and a pacing profile. Read the neutral split ledger before adding adjustments so a unit mistake is easier to spot.
4. Use Finish adjustment for a percentage change in moving time. Add whole planned stops, seconds per stop, and their placement separately because stops are added after the percentage adjustment.
5. Compare Projected finish, neutral baseline, average pace, split checkpoints, and scenario spread. Correct any invalid time or non-positive training estimate before using the plan.

Interpreting Results:

Projected finish is elapsed time after the selected base model, percentage adjustment, and planned stops. Average pace and speed are calculated from that final elapsed time, so both include pauses. The neutral baseline excludes the adjustment and stop budget.

• In direct mode, the result is an exact conversion of the entered target, not an assessment of whether the runner can sustain it.
• In recent-race mode, the distance ratio measures how far the projection stretches. When the larger distance is at least four times the smaller one, the result explicitly warns that it is a wide sensitivity estimate.
• In training mode, compare predicted race speed with average training speed. A large ratio is a reason to distrust the single finish time and inspect the scenarios.
• A slow checkpoint may contain a planned stop or extra profile weight. Check segment time and stop time before changing the moving pace.

Small changes that move the scenario finish by several minutes reveal a fragile goal. Use the resulting range to set checkpoints, then compare it with a recent long effort and the expected course conditions.

Technical Details:

Distance is normalized to metres and time to seconds before pace, speed, checkpoints, and scenarios are derived. One international mile is 1,609.344 metres, and the marathon distance is 42,195 metres. Display formatting happens after the underlying seconds are calculated.

Formula Core:

Each planning mode produces a base moving time. The percentage adjustment applies to that moving time, and planned stop seconds are added afterward.

For direct pace, D is kilometres and P is seconds per kilometre. Recent-race prediction uses source time T₁, source distance D₁, target distance D₂, and Riegel exponent p. The default exponent is 1.06 and the accepted range is 0.90 to 1.20. Training-mode marathon minutes M use weekly kilometres K, average training speed V in km/h, and whole runs per week R. The final equation uses adjustment percent a, stop count n, and seconds per stop s.

Transformation Core:

Checkpoint weights convert one adjusted moving time into segment times without changing the total. Even pacing uses uniform weight by distance. Controlled and negative profiles assign progressively less time later in the event; the negative profile applies the stronger shift. Late fade keeps the first 65% slightly faster, then increases weight toward the finish. Stops are placed at normalized course positions and added to the segment that contains each position.

The five scenario clocks depend on mode. Direct planning compares the current result with neutral, 3% faster, 3% slower, and 5% course-stress cases. Race prediction varies exponent and adjustment. Training mode varies weekly distance, run frequency, and course stress. These are deterministic comparisons, not probability intervals.

Accuracy Notes:

Race prediction models summarize limited evidence and do not measure current health, terrain, weather, fueling, or fatigue resistance.

• Prefer a recent all-out race on a known distance when using the Riegel path.
• Keep units, stop assumptions, and adjustment values fixed when comparing plans.
• The training equation is especially sensitive to its three inputs and may produce aggressive changes; use it as a scenario check.
• Use certified course distance and official timing when a qualifying standard is involved.
• The calculations run in the browser and are not sent to a dedicated prediction service.

Worked Examples:

References:

• Competition and Technical Rules - 2026 Edition, World Athletics, 1 January 2026.
• Athletic Records and Human Endurance, American Scientist, May-June 1981.
• Prediction of marathon performance time on the basis of training indices, Journal of Human Sport and Exercise, September 2011.