BMI / BMR / TDEE / Macros

For adults aged 20 and over. BMI is a screening measure, not a diagnosis or direct body-fat measurement. This tool does not prescribe a diet or handle pregnancy, childhood growth or clinical nutritional needs.

Equations

BMI = kg / metres². Adult reference categories are below 18.5, 18.5 to below 25, 25 to below 30, and obesity classes starting at 30, 35 and 40. Classification uses the unrounded BMI. Reference-weight bounds are 18.5 × height² and 25 × height²; the upper bound is excluded and displayed bounds are rounded.

Simplified Mifflin–St Jeor resting energy: 10 × kg + 6.25 × cm − 5 × age + 5 for the male reference, or −161 for the female reference. This predicts resting energy, not a measured metabolic rate. TDEE multiplies it by an illustrative activity factor from 1.2 to 1.9. These factors and day-per-week captions are rough scenarios, not individually measured expenditure. Target = TDEE + the chosen offset.

Macros

Five percentage presets allocate the full target to protein/carbohydrate/fat. The high-protein scenario allocates 2 g/kg to protein and divides the remaining energy equally between carbohydrate and fat. Protein and carbohydrate use 4 kcal/g, fat 9 kcal/g. If protein alone exceeds the target, the scenario is rejected. Displayed grams/kcal are rounded; their reconstructed energy can differ slightly from the unrounded target. Waist/height is shown numerically without diagnosing a BMI category from it.

Inputs and limits

Switching units converts height, weight and optional waist using 1 in = 2.54 cm and 1 lb = 0.45359237 kg; converted inputs are rounded to six decimals. Commas and decimal points are accepted. Invalid text remains editable and produces no estimate. Whole age 20–120, height 50–300 cm, weight 1–1000 kg and optional waist above 0 through 500 cm are software limits, not the validation range of the clinical equation. Nonpositive energy/targets and targets above 50000 kcal/day are rejected.

There are six macro presets and no custom percentage editor. Inputs are not saved across navigation.