I measure it using a handheld ultrasound device. Bodymetrix I think it's called. I also have a DEXA scan done every 2 to 3 months. The bf % estimate from the scan comes in at a 2 or 3 points above the bodymetrix device estimate.
Thinking about it....this might be because my abs are somewhat more developed than before and tend to make the waist slightly bigger (maybe half to one inch) than would be the case if I did not work out.
Interesting. Those results are within a small range. Most other "do-it-at-home" measurement tools have a much larger deviation from DEXA scans.
News alert: There is still no reliable way to calculate body fatness for all kind of people, but here is a fairly good and cheap device to use:
Lol...a mirror is your 1st port of call. But if u need to figure out how much macros to consume, a decent estimate of bf % is required.
Eating is the biggest cause of death. If you didn't eat too much wouldn't need all these measures of bogus fat analysis. Its not the fat its the calories that are killing you.