How calculations are selected
Each tool uses a formula suited to its purpose. Examples include Mifflin–St Jeor for resting energy, heart-rate reserve for training zones, Epley for estimated one-repetition maximum, and the Cooper equation for field-estimated VO₂ max.
Input validation
Every numeric field has a practical minimum, maximum, and increment. Values outside those limits are rejected with a specific message. Related inputs are checked together when necessary—for example, a barbell target cannot be below the empty-bar weight.
Rounding and units
Calculations use full numeric precision internally. Results are rounded only for display. Inputs use metric units to keep equations consistent and reduce conversion ambiguity.
What accuracy means here
An equation can be implemented correctly and still differ from a laboratory measurement or real-world outcome. Population equations summarize typical relationships; genetics, health, technique, environment, equipment, and measurement quality create individual variation.
Privacy model
Calculator inputs remain in your browser. There is no account system, personal profile, health database, or server-side storage for measurements.