Marathon Fuel Plan Calculator
Only explicit, user-tested inputs are used. No target, interval, serving or hydration volume is recommended. The first event is at the supplied offset, including zero; later events are offset + k × interval. Events after the finish are excluded; finish equality uses your selected boundary. A schedule may have zero events. Continuous target and discrete intake are different quantities. Calculations use exact decimal fractions; displayed numbers are full-precision JavaScript representations, not physiological predictions.
Marathon Fuel Plan Calculator
Only explicit, user-tested inputs are used. No target, interval, serving or hydration volume is recommended. The first event is at the supplied offset, including zero; later events are offset + k × interval. Events after the finish are excluded; finish equality uses your selected boundary. A schedule may have zero events. Continuous target and discrete intake are different quantities. Calculations use exact decimal fractions; displayed numbers are full-precision JavaScript representations, not physiological predictions.
A QUICK WALKTHROUGH
How to use this tool
- Enter your tested values and choose every mode and unit.
- Choose duration or distance and pace, enter your tested intake and timing, then calculate and inspect every event before exporting the same report.
Equations
T=d×p; G=T×r/60; t(k)=o+k×i; E=f+c×v; A=N×E; R=60×A/T.
Explicit user schedule
Only explicit, user-tested inputs are used. No target, interval, serving or hydration volume is recommended. The first event is at the supplied offset, including zero; later events are offset + k × interval. Events after the finish are excluded; finish equality uses your selected boundary. A schedule may have zero events. Continuous target and discrete intake are different quantities. Calculations use exact decimal fractions; displayed numbers are full-precision JavaScript representations, not physiological predictions.
Additional complete scenarios (optional)
One scenario per line: name | duration in minutes | target g/h | food g | drink g/ml | drink ml | offset minutes | interval minutes. Enter 0 and 0 for no drink. Boundary choice applies to all scenarios. Up to 20 additional scenarios; at most 5,000 events per scenario and 10,000 combined.
GOOD TO KNOW
Common questions
Does this choose my nutrition target?
No. Supply targets tested with qualified guidance. This tool only totals your schedule and does not assess medical suitability.
Finish boundary
Only explicit, user-tested inputs are used. No target, interval, serving or hydration volume is recommended. The first event is at the supplied offset, including zero; later events are offset + k × interval. Events after the finish are excluded; finish equality uses your selected boundary. A schedule may have zero events. Continuous target and discrete intake are different quantities. Calculations use exact decimal fractions; displayed numbers are full-precision JavaScript representations, not physiological predictions.