Health

Fueling calculator

Carbs, fluid and sodium for any run, and when to take them.

Say what you are running and the plan builds itself. Then tune it to you: your body, the weather, what you carry. It works the same whether or not you have an account.

Training mode: practice fueling, train your gut, and experiment in small steps.

Fluid in

My fueling plans

Select Marathon Workout

Pulled live from your Marathon plan

Your run

Auto-filled from a workout above, or enter your own

Workout

Start time (optional)

Tune it

Optional. Whatever you skip is estimated and listed.
You

Athlete

Weight in
Conditions

Environment

How to measure your sweat rate

Weigh yourself without clothes right before and right after an hour's run, without peeing in between. Every pound lost is about 16 oz (450 ml) of sweat; add what you drank during the run. Measure again in hot weather: it changes a lot.

Sodium

Sodium

What you carry

Fueling Preferences

Homemade Drink

Bottles

Targets (total across bottles)

Ingredients

60 mg in bottles 2 and 3 is 120 mg from the drink. Leave the bottles blank for none.

Fueling Library

Pre-Workout Fuel

Simple, cheap, easy to digest

Your answers

Change any part

Keep this plan

Calculate a fueling plan above to build a saved plan.

Keep it everywhere

You're using the calculator without an account. Your answers, drafts and saved plans stay in this browser on this device, and nothing is sent anywhere. Sign in with Google to keep them in your own account, on every device.

Not now is fine: everything on this page works without an account. Want fueling built into your training? Apply to train with me.

No plan yet — here is what happens next

  1. Say what you are running: distance, time or pace.
  2. Add the gels and drink you carry, or keep the plan's homemade drink.
  3. Your plan shows here, with the Fuel Clock on top: the next gel or drink, when it is due, and how much is left to drink.

Have a saved plan? Open it from My fueling plans.

My Fueling Plans

Tested runs

Fueling recommendations are estimates for training and planning purposes and are not medical advice. Individual needs vary based on physiology, conditions, intensity, and experience.