Resources · Fuel calculator
Race fuelling calculator
How many gels to carry for your target time, and how far apart to take them. Worth doing for anything over about ninety minutes.
Carry
8 gels
Total carbs
200g
One every
30min
Based on 25g carb gels across a 4:00:00 finish. Take the first at 30 minutes rather than waiting to feel empty — by then it's too late to catch up.
Your plan, on the clock
0:30
1:00
1:30
2:00
2:30
3:00
3:30
4:00
When to start
For races over 90 minutes, take the first gel at about 45 minutes — earlier if it's hot.
Hydration
400–800ml an hour, adjusted for sweat rate and temperature. Gels need water to absorb.
Test it first
Rehearse the whole plan on a long run — brand, timing and volume together.
Not sure of your pace yet?
Set a target pace and see your finish time at this distance, plus your training paces.