Carbohydrate Intake Calculator
Work out daily carbohydrate needs from body weight and training load.
Please note: For general information only. This is not medical advice — speak to a doctor or registered dietitian before changing your diet, training or medication.
What the Carbohydrate Intake Calculator does
Carbohydrate requirements are set by training load rather than body size alone, which is why sports nutrition guidance is expressed in grams per kilogram of body weight at a given volume of training. Fuelling during a session follows separate rules, limited by how fast the gut can absorb rather than by demand.
Formula
Daily carbohydrate = Body weight (kg) × grams per kg for the training loadCalories from carbohydrate = grams × 4Recovery = 1.0 to 1.2 g per kg in the first hour after a hard session
Inputs explained
| Input | Unit | Required | Notes |
|---|---|---|---|
| Units | one of 2 options | Yes | — |
| Body weight | kg or lb | Yes | Accepts 20 or more, up to 300. |
| Training load | one of 6 options | Yes | — |
| Longest session | hours | Optional | Accepts 0 or more. |
| Total daily calories | cal | Optional | Accepts 0 or more. |
| Meals and snacks per day | number | Optional | Accepts 1 or more. |
How to use it
- Choose Units and Training load.
- Enter Body weight.
- Optionally add Longest session, Total daily calories and Meals and snacks per day.
- Select Calculate.
Worked example
A 70 kg athlete training 1 to 3 hours a day.
- Weight
- 70 kg
- Load
- Endurance, 1 to 3 hours (8 g/kg)
70 × 8 = 560 g of carbohydrate a day, which is 2,240 calories — about 140 g per meal across four meals.
Frequently asked questions
Why is intake given per kilogram?
Because glycogen storage capacity scales with muscle mass, and muscle mass scales roughly with body weight. A per-kilogram figure travels across athletes of different sizes.
Why cap fuelling at 60 g an hour unless mixing sugars?
Glucose absorption saturates its intestinal transporter at around 60 g an hour. Fructose uses a different transporter, so combining them raises the ceiling to about 90 g without gut distress.
Method and sources
Method. Body weight multiplied by a grams-per-kilogram target selected for training load, following the ranges used in sports-nutrition guidance.
Assumptions
- The reader is a healthy adult without diabetes or another condition requiring managed carbohydrate intake.
- Training load is described honestly; the ranges separate by hours of hard training a day, not by intention.
Limitations
- The g/kg ranges are guidance for fuelling endurance training. They are not a general dietary recommendation and are substantially more than a sedentary adult needs.
- Published ranges differ between sources and are broad within each band, so treat the output as an order of magnitude rather than a target to hit precisely.
- Anyone managing blood glucose should take carbohydrate targets from their clinical team, not from a calculator.
Sources
- Sports-nutrition position stands on carbohydrate intake for training and competition — Varies by body; the presets span the ranges these publish. The span of the g/kg presets, cited generically because no single source establishes the whole ladder.