TLSFree tools
Health calculators, science-backed, no signup.
Estimate your TDEE, VO2 Max, training zones, and sleep score. Each tool is run entirely in your browser — nothing leaves your device.
TDEE Calculator
Total Daily Energy Expenditure — how many calories you burn per day. Foundation for any cut, bulk, or maintenance plan.
Source: Mifflin-St Jeor
VO2 Max Estimator
Estimate your VO2 Max from a 12-minute run, a sub-max heart rate test, or your resting heart rate.
Source: Cooper
Heart Rate Zone Calculator
Five training zones from your max heart rate. Karvonen method uses heart rate reserve for accuracy.
Source: Karvonen & Vuorimaa
Sleep Score Estimator
Estimate your sleep score from duration, deep%, REM%, and awakenings. Compare against commercial wearables.
Source: Approximation of Fitbit + Oura sleep scoring. Not validated against PSG.