Clear methods.
Honest estimates.
A calculator should let you see how it reached a result.
Formula first
Each page explains equations, units, scope, and assumptions. Original research and official guidance are linked. Activity multipliers and model averages are distinguished from original equations.
Estimates stay estimates
TDEE and 1RM are predictions. BMI is a screening measure. Running splits assume constant pace. Results are not medical or training prescriptions.
Precision and checks
We retain precision internally and round for display. BMI categories use unrounded values. Checks cover reference examples, unit conversions, category boundaries, invalid inputs, and partial running splits.
Editorial transparency
Methods documented 9 November 2026. No clinical reviewer is claimed. These tools provide general information. Explanations and checks should be updated whenever methods change.
Adult scope
BMI uses CDC categories for ages 20 and older. The TDEE pilot accepts ages 20–78 with additional input limits. These are safeguards, not validated clinical boundaries. Pregnancy, pediatric growth, and medical nutrition need different assessment.