Body Recomp Calc Guide
About Body Recomp Calc
Body Recomp Calc is an independent, ad-supported calculator site run by a small editorial team. We are not dietitians, doctors or coaches, and we do not claim to be. What we do is read the published equations and position papers, implement them exactly as written, and show our working so you can check it.
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The site exists because most macro calculators hide their method. Ours does not. Calories come from the Mifflin-St Jeor resting energy equation (Mifflin, St Jeor et al., American Journal of Clinical Nutrition 1990;51(2):241–247), multiplied by one of five conventional activity factors. The goal adjustments (0% to maintain, −10% for recomposition, −20% to cut, +10% for a lean bulk) and the default 25% fat share are common starting-point conventions, not clinical prescriptions, and every page says so. The protein range of 1.6–2.2 g per kg is taken from Morton et al., British Journal of Sports Medicine 2018, with the ISSN position stand on protein and exercise (Jäger et al., 2017) as a cross-check. Food protein values come from USDA FoodData Central.
We re-read every cited source at least twice a year and after any of them is revised. The last full check was 19 September 2026, and each calculator page carries its own updated date.
If a number looks wrong, or a formula does not match the source we cite, please contact us with the inputs you used and we will correct it or explain the difference.
Why this site exists
Most macro calculators return a number with no working shown. You cannot tell which equation produced it, what assumptions were baked in, or whether the protein figure reflects published research or a rounded guess. When the number is the whole product, that matters.
Every figure here names its formula and its source. The calorie target uses the Mifflin-St Jeor equation; the protein range comes from the ISSN position stand on protein and exercise; food values come from USDA FoodData Central. If a result looks wrong, you can follow it back to where it came from.
What we do not do
There is no sign-up, no account and no stored data; the calculators run in your browser and nothing you type is sent anywhere. We do not sell supplements, meal plans or coaching, so no result is steering you toward something to buy.
We also do not claim precision the method does not support. Predictive equations estimate energy expenditure with meaningful individual variation, which is why every page tells you to adjust from real-world data after two to three weeks rather than treating the first number as fixed.
Limits worth knowing
These tools are general information, not medical or dietary advice. They do not account for medical conditions, medication, pregnancy or eating disorders, and are not suitable for under-18s. If you are working with a clinician or dietitian, their guidance takes priority over anything calculated here.