Race hydration planner

Plan your drinks, refills and fuel for a run, ride or hike. Enter the course details once and keep the stops, supplies and timing together on one card.

Jump to the pocket card

Build your race-day plan

Enter your finish time and the organiser’s stations. You’ll see when you might reach each stop, what to carry and where you can refill.

Activity

Choose a distance

Distance

Expected finish time

hmin

Aid stations and refill stopsHow would you like to enter the stops?

Use the organiser's map to enter each distance from the start. Mark where you can refill a bottle to see how much to carry between stops.

Paste station distances

Distances from the start (km)Separate the distances with commas or new lines.

What can you carry?

Capacity per bottle or flask (ml)Bottles or flasks you’ll carry

Weather and sweat rateOptional

Expected temperature (°C)Expected humidity (%)

This checks the weather now. Enter the event forecast if you’re planning ahead.

Expected effortSweat rateWhat will you drink?

FuellingOptional

Add fuelling to this plan

Notes for your card (optional)

View my plan

This example starts with a half marathon. Change the details to make it yours.

Your fluid planning range

Per hour300–600 ml

Across the event0.63–1.25 L

This is a broad estimate. A sweat test from a similar session gives you a more personal starting point.

Race pocket card

21.098 km · 2h 05m expected finish

Longest gap between stopsStart to Finish · 21.098 km · 2h 05m

Longest gap without a confirmed bottle refillStart to Finish · 21.098 km · 2h 05m

What you can carry500 ml capacity · 625–1,250 ml planning range for that refill gapYour bottles hold less than the top of this range. Check supplies, add capacity or plan where you can stop for a drink.

Start0 km · 0 min elapsed
Finish21.098 km · 2h 05m elapsed

Times assume an even pace. Check the organiser’s latest station details and allow for hills and queues. Use the fluid range to plan what to carry and let thirst and comfort guide what you drink.

Avoid drinking enough to gain weight during the event. Stop and seek medical help if symptoms are concerning, including severe headache, nausea or confusion.

How the planner works

The planner uses your finish time to estimate when you’ll reach each stop at an even pace. Enter a measured sweat rate and the planner uses 60–90% of that rate, rounded, as a starting range. Without a measurement it shows a broader range based on the temperature and humidity you entered.

The card shows your longest stretch between stations and your longest stretch without a confirmed bottle refill. These can differ. A station with cups might be a good place to drink, but you’ll need to carry enough for stretches where you can’t top up.

A two-hour half marathon with a measured 0.8 L/hour sweat rate

At that rate you’d lose about 1.6 litres of sweat in two hours. The starting range is 475–725 ml per hour, or 950–1,450 ml for the event. If you can refill a 500 ml bottle at around the halfway point, check how it fits the first and second halves.

Try your plan on a long run in similar conditions. Drink according to thirst and comfort, and avoid drinking enough to gain weight during the event.

What to check on the course map

Use the latest map and enter each station’s distance from the start.
Check where you can fill a bottle and where the organiser only hands out cups.
Note familiar drinks or gels and check whether you’ll have water when you plan to take them.
Check the final stretch to the finish and decide if you need to carry a reserve.

Try a sweat-rate test in training. For a route with few stops, you can also compare bottles, belts and vests for the distance you’ll cover between refills.