How to measure body fat

So I got my calipers and measure tape in today. Using the calipers (on my stomach only) I am getting a little over 26%. Using the tape measure and measuring my neck, waist and plugging the numbers into an Army PT app, I am getting 23%.
When my son gets home, I am going to have him help me do the 4 location test with the calipers.
I wish I could have gotten a measurement when I started as I know I have lost quite a bit of fat in the chest shoulders and arms.
I guess more than anything at least I will have accurate measurements now to look at my progress. But do you guys know which is more accurate, the caliper test or the Army test? Just curious. Also, is there a certain time that is better to measure? I mean fat is fat, right? Not going to change from morning to evening.
I will compare these numbers to my scale as well, just to see how far off/consistent it is.