If you are id suggest you start eating. When i was 18 I used to be 175lbs with a 11% BF. Apart from having a ridiculous 6 pack i was streak of wiry weak ****. I only felt stronger as i got heavier and used more resistance exercises. If your intention is to engage in sport a BF that low isn't helpful.
I had around 7-8% bodyfat once in my life(I don't know how accurate the test was). I competed at 19 yo in a bodybuilding show. I've never been more miserable. I sustained that for a very short period of time.
boxers get it cos they train their asses off- but if you re aiming to hit a number for the **** of it- it can get a bit obsessive and unhealthy. i got those scales too- and was initially 16 percent- had a six pack but wasnt cut up, i d eat , train and live to get it sub 10- was ripped up but and only could maintain it for a while once i started living a more balanced routine. with that being said though, it is a useful yardstick to see progress- if you re training for trainings sake, and not body fat goals. my trainer said it best, be happy with what youv e got, we can all get sub 7 percent - but most of us have to suffer and kill ourselves for it- and in the end its only for a moment. even bodybuilders and actors, and boxers are only that ripped for a moment, a show, a photoshoot, a fight, a movie, etc.
Bodyfat readings are only relevant in comparison to yourself...that made no sense did it...how can I put it... Your scale is fine. It probably doesn't display your actual bodyfat %, but if you always use that scale, it should accurately reflect increases/decreses. I have one as well. I also use calipers, and they usually read 1-1.5% higher than the scale. (Scale says I'm 9.4%, calipers say 10.5-11%). You just look t it every day and see if the percentage is going up or down. Underwater weighing is the most accurate way to do it, but why would you want to go through that? But you can't compare your bodyfat readings with someone else's. They might get a reading from another scale, a set of calipers, etc. And all readings have a small window of error anyway. But if it's at 20% and you're an athlete then yeah you could stand to lose some pounds for sure.