I posted this info on the other question about weigh-ins so I might as well post it here, too. This should give you some idea of the averages you can expect. Of course, if your calf is large framed he will probably need to weigh more than 1300 lbs.to grade Choice.
Our 2010 county fair averages were:
Dec. Weigh in Ave wt. 694 Range 552---885 lbs
Fair Weigh in Ave wt. 1311 Range 1140---1495 lbs
Average ADG 3.31 lbs/day Range 2.94---3.98
The best way to do it is to weigh the calf periodically so you know what he ways and how you are coming towards your target weight. Unfortunately, you may be like us and not have a scale on your farm so it becomes more difficult to get those weights. WE have hauled calves to the elevator's truck scale to weigh them in the past. This won't give you an exact weight but it will give you an estimate within 20 lbs or so.
There were 186 days between our Dec. weigh in and our fair weigh--in