Energy Availability Check: free energy availability calculator.
Enter what you eat, what your training uses and your fat free mass. See your energy availability and what the research says about it.
Your energy availability
Energy left for your body each day
33.3kcal per kg fat free mass
At or above about 30, the level the IOC's 2023 consensus uses as its marker. This is a fact about the numbers you entered, not a diagnosis.
Mountjoy 2023Jeukendrup 2024These numbers are estimates: a food log and a watch both miss by a lot, and the 30 line is debated (Jeukendrup 2024). If your result worries you, talk to a sports dietitian or a doctor; they can measure what this only estimates.
If food, weight or training feels hard to control, you are not alone and help is free: ANAD in the US, Beat in the UK, or your doctor.
Hand it to your AI
Your AI can check these numbers against your training and adjust them. The prompt has your results filled in.
See the prompt
I eat about 2,200 kcal a day and my training uses about 600 kcal a day. My fat free mass is about 48 kg. That puts my energy availability at about 33.3 kcal per kg of fat free mass a day. The IOC's 2023 REDs consensus associates values below about 30 with health and performance risk. Help me understand what this means for my training, look at how I've been fueling and recovering, and tell me plainly if I should see a sports dietitian or a doctor.
Gemini, Grok Bot, Dots, Muse and Cue: copy the prompt and paste it in.
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How it works
How the Energy Availability Check works.
Energy availability is the energy left for everything your body does outside training, after your training has taken its share. It is counted per kilogram of fat free mass, because that is the tissue that uses most of it.
When it stays low for a long time, the body starts saving energy where it can: hormones, bone, immunity, recovery. The IOC's 2023 consensus calls this Relative Energy Deficiency in Sport, or REDs, and it can happen to anyone who trains, at any body size.
The consensus uses about 30 kcal per kg of fat free mass a day as a marker below which those risks rise. This calculator shows where your numbers fall against it. It is a fact about the numbers you entered, not a diagnosis. Food logs and watches both miss by a lot, and some researchers question how well a single line predicts problems. A sports dietitian or a doctor can look at the whole picture.
The formula
- energy availability = (energy eaten − exercise energy) ÷ fat free mass (kg)
- fat free mass = weight × (1 − body fat % ÷ 100)
The science
Where the numbers come from.
These are the same rules Memory.fit's engine uses when your AI asks it for a number, read from one registry of cited sources.
Mountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). British Journal of Sports Medicine 57(17):1073-1097.
Consensus statement · 2023 · doi:10.1136/bjsports-2023-106994
Jeukendrup AE, Areta JL, Van Genechten L, et al. Does Relative Energy Deficiency in Sport (REDs) Syndrome Exist? (2024). Sports Medicine 54(11):2793-2816.
Review · 2024 · doi:10.1007/s40279-024-02108-y
Example
A worked example.
A 60 kg runner with 20% body fat who eats about 2,200 kcal a day and burns about 600 kcal a day in training.
- 1Fat free mass: 60 × (1 − 0.20) = 48 kg.
- 2Energy left after training: 2,200 − 600 = 1,600 kcal.
- 3Energy availability: 1,600 ÷ 48 = 33.3 kcal per kg of fat free mass a day, above the 30 marker the IOC consensus uses.
Questions
Energy Availability Check: questions.
The energy left for your body after training, per kilogram of fat free mass: what you eat minus what your training uses, divided by your fat free mass.
Relative Energy Deficiency in Sport: the health and performance problems that can follow when energy availability stays too low for too long. It affects athletes of every sex and body size.
Not always, and not from one day. The IOC consensus uses about 30 as a marker of rising risk, and researchers still debate the exact line. A low result is a reason to look closer with a professional, not a diagnosis.
Only as accurate as its inputs. Food logs often miss what we eat, watches estimate training energy, and body fat readings vary by method. Treat the result as a rough guide.
A sports dietitian or a doctor who works with athletes. If food, weight or training feels hard to control, ANAD in the US or Beat in the UK offer free support.
Not medical advice. These numbers come from published research on groups of athletes. Your own needs can differ; talk to a doctor or a sports dietitian about any health condition.