I went to a clients house today to give a ext. on installing rocks and border around the front of her house. The area is 18 inches(1.5 ft.) by 51 ft. When I punched it in my calculator I put in 18 x 51 instead of 1.5 x 51. The rocks that she had picked out were 3$ a bag and I figured it would take 100 bags. She approved it (surprised at the price) and when I left it suddenly hit me what I had done. Should only take about 12 bags(Im saying 20 to be on the safe side). I have never messed up that bad before, Im usually good at underestimating. Should I tell her it will be cheaper or just take it in case there is something I might have missed figured. My actual cost in material is only about 176 instead of the 400 plus I had figured. Will probably take me about 4-5 hours to do, give or take a little. I take great pride in my honesty just hate to call her back and make me look stupid. On the other hand if it takes me longer than I estimated in time will come out ok. Just wanted to ask you guys who have done a lot more landscaping than me your thoughts. I have not done a whole lot of this kind of work, mostly just regular yard maintinance and did not want to loose my butt till I get better at figuring this kind of work. The lady has been a real PITA though for a new client. I quoted her around 650 for the job. I usually figure my labor around 30-35 per hour for this kind of work. I know, I know about the dollar a minute but it will not flush in my area.