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Cycling Nutrition Calculator
How much to eat and drink — hour by hour.
Upload your GPX and get a fuel plan based on your route's actual power demands.
How it works
01
Upload your GPX
Any route from Komoot, Strava, Garmin or Wahoo. The file contains your elevation profile used to calculate power demands per segment.
02
Set your weight and tempo
Rider weight, bike weight and tempo estimation method — average speed, FTP, or actual GPS recording times.
03
Power model runs per segment
Mechanical power is calculated for each GPS point using speed, gradient and rider mass. Surface type adjusts rolling resistance and energy cost.
04
Get your hour-by-hour fuel plan
Energy expenditure is aggregated into 60-minute windows. Each hour shows kcal burned, grams of carbs, number of gels and fluid needed.
Step 1 — Upload your GPX file
Drop a GPX file here
or click to browse
Step 2 — Your weight
How the calculation works
What is a cycling nutrition plan?
A cycling nutrition plan is a structured schedule of carbohydrate, fluid and electrolyte intake for a specific ride, broken down hour by hour. Unlike generic sports nutrition advice, a route-specific plan accounts for the actual power demands of each section of the ride — steeper climbs burn significantly more kilojoules than flat sections at the same speed.
This calculator uses a physics-based power model derived from your GPX file. It calculates the mechanical power required at each GPS point using speed, gradient, rider mass, bike mass, air resistance and rolling resistance. The power output is then converted to kilojoules of mechanical energy and to kilocalories of metabolic energy (applying a 23–25% mechanical efficiency factor). Carbohydrate intake targets are set at 60–90 g per hour depending on effort level, with gel equivalents provided for easy on-bike reference.
The plan is designed for endurance cycling events: gran fondos, sportives, ultra-distance rides, gravel races, and long training rides. It is not designed for criteriums, track cycling, or efforts under 60 minutes where pre-ride glycogen loading is typically sufficient.
Who needs a cycling nutrition calculator?
This tool is used by amateur cyclists preparing for their first gran fondo who want to know how many gels and bottles to carry, by experienced riders who have bonked (run out of glycogen) on long rides and need a more structured approach, by coaches building nutrition protocols for athletes, by adventure cyclists on multi-day bikepacking routes where resupply planning matters, and by anyone riding a route with significant elevation gain where the caloric cost differs substantially from a flat-road estimate.
Frequently asked questions
How many gels do I need for a 100 km ride?
It depends on the elevation and your pace. A flat 100 km ride at moderate pace takes approximately 3–3.5 hours and burns around 1,800–2,200 kcal. At 60 g carbohydrate per hour, you need 8–10 gels (each 25 g carbs) or equivalent. A hilly 100 km ride with 2,000 m of climbing can take 4.5–6 hours and burn 3,000–4,000 kcal, requiring 12–16 gels. Upload your GPX file to get an exact figure for your specific route.
What is the 60–90 g carbohydrate per hour rule?
Research shows the gut can absorb approximately 60 g of glucose per hour. Combining glucose and fructose in a 2:1 ratio increases absorption to 90 g per hour because they use different intestinal transporters. Most energy gels contain 20–25 g of carbohydrates. For efforts over 2.5 hours at high intensity, targeting 60–90 g/hour is the current sports science consensus for endurance performance.
How does the power model calculate calorie burn?
The calculator reads your GPX elevation data and estimates the mechanical power needed at every GPS point — accounting for three forces: air resistance (which grows with the cube of your speed), rolling resistance (surface and weight), and climbing (gradient and mass). Power in kilojoules converts to food calories at roughly a 1:1 ratio, which is the standard used by Garmin, TrainerRoad and Stages.
What is bonking and how does nutrition prevent it?
Bonking (or "hitting the wall") is the sudden onset of extreme fatigue caused by depleted glycogen stores. Glycogen is the primary fuel for high-intensity cycling, stored in muscles and the liver. A trained cyclist stores approximately 1,800–2,000 kcal of glycogen — enough for roughly 90 minutes at race pace. Consuming carbohydrates during the ride extends this supply indefinitely. Missing nutrition intake for even one hour at high effort can lead to bonking on a long ride.
How much water should I drink on a long ride?
A general guideline is 500–750 ml per hour in moderate temperatures, and 750–1,000 ml per hour in hot conditions above 25°C. Electrolyte loss (sodium, potassium) becomes significant in rides over 2 hours and in high-sweat conditions. Add electrolyte tablets or drink sports drinks rather than plain water on rides exceeding 2 hours to avoid hyponatraemia (low sodium from overdrinking plain water).
Should I eat differently for a hilly route versus a flat route?
Yes. Climbs dramatically increase power output — a 6% grade at 15 km/h requires roughly 3–4× more power than flat riding at the same speed. The caloric cost of climbing is therefore much higher per minute. On a hilly route, you need to eat more in total and time your intake before major climbs, as the gut is less efficient at absorbing nutrition during very high-intensity efforts.
Can I use this calculator for a mountain bike or gravel ride?
Yes. Select the surface type in the form — Road, Gravel, MTB or Cobbles. Each surface applies the correct rolling resistance and an energy multiplier for body movement and terrain difficulty: Gravel adds 15%, Cobbles 20%, and MTB 28% to the base energy cost. The plan automatically adjusts.
How does elevation gain affect calorie burn?
Climbing adds a direct gravitational power requirement. Every 100 m of altitude gained burns approximately 30 kcal per 10 kg of combined rider and bike weight (from P = mgh). A 75 kg rider on a 9 kg bike climbing 1,000 m of total elevation burns an additional 250–300 kcal from climbing alone, on top of the baseline cost of moving through air and overcoming rolling resistance. The GPX elevation profile is used to calculate this precisely for your specific route.