Note that these are the formulae for men. All of these come with blurry lines around what the max really is, even when measured in a consistent population (men of same age, same fitness level, same sports team, can have wildly different HRmax values). These formulae are based on average populations but that’s the best guide you can have without getting your own custom ratings.
For my age and weight these all give pretty consistent numbers across the key ranges.
It is also clear that my general HR numbers from recent runs are way too high. My two mile runs are generally in the 85-100% range which would be very difficult to maintain over distance.
updated info: Note that I update this set of calculations as I find more info. The Measured HRMax and Heart Rate Reserve columns came from later research and testing. Follow the links for more info on those.