when dogs are skinny its kinda obvious The best guide is honestly your hands and eyes, not just the scale. You should be able to feel the ribs easily without pressing hard, and see a visible waist from above and a tuck from the side. If the ribs disappear under a layer of padding, that's a sign to cut back. I ordered a new scale from buygoods https://buygoods.pissedconsumer.com/review.html to track my dog's weight more carefully. Breed and frame matter a lot too, so compare against standards for your specific dog.