Standard TDEE calculators were built for average sedentary adults — they consistently under-shoot for CrossFit athletes. This page is the TDEE calculator with notes written specifically for CrossFit: the Mifflin-St Jeor BMR is reliable, but the activity factor is where most athlete calculators get it wrong. Pick honestly, validate against your weight trend, and the number below becomes the foundation of every plan you build.
The classic Mifflin-St Jeor activity factors (1.2 to 1.9) were calibrated against general-population data. For CrossFit athletes, three things break that calibration: weekly training volume is high, exercise intensity creates an after-burn (EPOC) the formula does not see, and NEAT outside training sessions tends to be higher in athletes with strong movement habits.
The result is that 'moderate' often understates real-world TDEE for CrossFit by 200–500 kcal. The fix is not picking a magic number — it is choosing 'very' or 'extra' when training is genuinely intense, then validating against weight trend.
For CrossFit athletes, training calorie burn scales with both duration and intensity. A 60-minute high-intensity session typically burns 400–700 kcal during the session plus 50–150 kcal of EPOC over the following hours. Strength sessions burn less during but more after; endurance sessions are the inverse.
What matters for TDEE planning is the weekly total, not the per-session burn. Two hard sessions a week ≠ five hard sessions a week, even at the same bodyweight. Pick the activity factor that reflects your honest training week, not your best one.
Under-fuelling is the single most common mistake for CrossFit athletes — chronically eating below TDEE, hitting performance plateaus, losing strength or recovery and blaming the program. Real TDEE for trained CrossFit is often surprisingly high; the calculator is a starting point, not a ceiling.
If performance is declining, sleep is poor or weight is trending down without intent, the answer is almost always more food. Add 200–300 kcal for two weeks and recheck. The calculator gives you the baseline; the body gives you the truth.
Inside AJYX, TDEE is recalibrated weekly from your real intake versus your real weight trend — so high-volume weeks bump the target up automatically, deload weeks bring it down, and the long-term drift as you build lean mass is captured without manual tinkering.
For CrossFit athletes this matters most around competition prep, season changes and travel. The static TDEE from a one-time formula always lags reality; the living TDEE from real data does not.
If you train 5+ hard sessions per week, 'very' (×1.725) is usually closer to truth than 'moderate'. Daily training or high-volume blocks justify 'extra' (×1.9). When in doubt, pick the higher level and adjust down only if weight trend says so.
No — that double-counts. TDEE with an honest activity factor already includes your typical training week. Only add extra calories for one-off long sessions or unusually heavy weeks that fall outside your normal pattern.
Within ~5–10% if the activity factor honestly reflects your week. Athletes with very high or very low body composition can sit outside that band; trust the weekly weight trend over any formula.
Either your activity factor is too low (most common), your training volume is higher than you logged, or NEAT is higher than you realised. Eat 200–300 kcal more for two weeks and recheck — the trend will tell you which.
Competition days demand more carbs around the event and slightly more total calories than a typical training day. Use TDEE as your weekly average, not your daily floor — eat to the event, not the calculator.