From what I have read, inexpensive home scales are most accurate for people who weigh in the vicinity of about 150 pounds. I also always weigh less at the doctor than at home, but I don't mind it, it's better than weighing more at the doctor than at home! I post my weight using my home scale since it is the one I have access to daily, but in the back of my head I know that I weigh a little less than my posted weight.

If you home scale is old, you might want to invest in a new one. The springs do start to wear out after a while and a new one might be somewhat more accurate.