How to build an ultramarathon aid-station plan

Start with the current official information

Open the current runner guide, course page, or organizer update. Record the race distance, scheduled start, aid-station order, cumulative distance to each station, overall cutoff, and every checkpoint cutoff. If two official documents disagree, do not average them or choose the more convenient value. Ask the organizer which version controls.

Also note whether a station allows crew, has a drop bag, offers water only, or requires a gear check. Those details do not change the calculator's arithmetic, but they change how much stop time belongs in the plan.

Confirm that station distances are cumulative

Aid Station Planner expects the total distance from the start to each station. Race documents sometimes publish both cumulative distance and segment distance, and it is easy to enter the wrong column.

Entering 8, 7, and 10 would put the second station behind the first. Enter 8, 15, and 25. The calculator checks station order, but it cannot determine which column of the runner guide you intended to copy.

Classify stops before assigning minutes

Do not give every checkpoint the same stop budget by default. Identify what you expect to do there. A water-only refill is a different job from finding a drop bag, changing layers, eating, treating a foot problem, and briefing crew.

• Pass-through: you may not stop, but leave a small budget if the station layout forces a walk or check-in.
• Quick service: refill, grab food, dispose of trash, and leave.
• Standard reset: refill, eat deliberately, use the toilet, or make one simple gear adjustment.
• Major stop: crew, drop bag, clothing change, shoe change, lighting setup, or several tasks together.

The categories are planning labels, not universal time standards. Use the stop-time budgeting guide to turn the actual tasks into minutes you can test during training.

Build the first timing card

1. Choose the calculation mode. Goal mode solves for the moving pace required to finish in a target elapsed time. Pace mode starts with an expected moving pace and projects the finish after stops.
2. Enter the official race distance and unit. Use the organizer's published distance rather than rounding a 50K to 31 miles.
3. Enter the local start date and time. The date gives overnight arrivals an unambiguous Day 2 or Day 3 label.
4. Add stations in course order. Enter cumulative distance, a recognizable name, and the stop budget for that visit.
5. Add the overall cutoff when published. The result shows the difference between projected finish and that cutoff.

Now open the calculator, build the card, and print it or save it as a PDF. Keep this first version as a baseline rather than treating it as a promise.

Audit departures, not only arrivals

Every stop shifts the departure from that station and every arrival after it. If an intermediate cutoff requires runners to leave by a stated time, the departure column is the relevant comparison. A runner can arrive before a cutoff and still leave too late after refilling or seeing crew.

Check the card in three passes:

• Course pass: station order and cumulative distances match the current guide.
• Clock pass: start time, overnight day labels, and published cutoffs use the same local time.
• Behavior pass: stop budgets reflect the tasks you plan to perform, including ordinary walking and searching time.

Recheck the plan during race week

Organizers may publish course changes, relocate aid stations, adjust access, or clarify cutoff rules after registration. Repeat the course and clock passes when the final instructions arrive. Reprint the card if any official number changes.

Finally, mark the card as a baseline. Terrain, elevation, heat, cold, darkness, congestion, navigation, and fatigue can all change actual arrivals. The value of the card is that it makes the original assumptions visible, so a runner or crew member can recognize when the race has moved ahead of or behind that baseline.