mine is 56.15 using RHR and age
Using your resting heart rate and age:
VO2 max = 15.3 x (MHR/RHR)
MHR = Maximum heart rate (beats/minute) calculated using age = 208 - (0.7 x age)
RHR = Resting heart rate (beats/minute) = number of heart beats in 20 seconds x 3
The Rockport Fitness Walking Test (RFWT) using a 1-mile (1.6-kilometer) walk:
VO2 max = 132.853 - (0.0769 x W) - (0.3877 x A) + (6.315 x G) - (3.2649 x T) - (0.1565 x H)
W = Weight (in pounds)
A = Age (in years)
G = Gender factor, G = 0 for females and G = 1 for males
T = Time to complete the 1-mile walk (in minutes)
H = number of heart beats in 10 seconds at the end of the 1-mile walk