Re: Hold your breath
There are several different methods but none is 100% accurate as ur basal metabolic rate depends upon your eating, activity levels, temp, age and gender. Several hand held devices can measure your oxygen input and C02 output to give an estimate of ur energy expenditure.
If u really want an equation, than here it is 655 + {4.35 weight in pounds} + {4.7 x height in inches} - {4.7 x age in years) (women)
there is different equation for men