offwidth
Level 10 Valued Member
As far as I am aware there are no reliable (valuable) methods of calculating HRmax.Polar calculated HRM is 161.
The way to do it accurately (if one needs it) is to do an HRmax test.
The best way is to have the test administered by a doctor. One with a defibrillator on standby.
There are some self tests, but I won't describe them here.