Try looking here

http://gardening.about.com/od/vegetable1/a/How-Much-Plant.htm

There is a link at the bottom of the first page that takes you to a chart. The chart shows recommendations for each plant for a family of 4.

Obviously how much to plant depends on whether you are just wanting to eat fresh or if you want to preserve some of the vegetables.

When the chart says a 10' row, figure the plant spacing and that will tell you how many plants you need.

Example. The chart recommends 10' row of carrots. Typical "row" spacing for carrots is 2".

10 foot row = 120 inches
120 inches divided by 2" row spacing is 60 plants
60 plants divided by 16 per square in sfg spacing is 3.75 squres.

So for a family of 4, the recommendation for carrots is 3.75 squares (60 carrot plants).

I hope this makes sense and is helpful. Reading back over it reminds me of math story problems. I'm bored, maybe I'll take the chart and work an excel program to figure all the squares out. Hmmm, I may have to do that.

Wow Momstar! That is an awesome link. I actually asked a similar question on the vegetable forum and they really could only give me a estimate. This website helps a ton, especially once you showed how to do the math and convert is to "sq ft garden terms!" Thank you so much!

Thanks, momstar. I went right to the site and got what I needed. BTW, I now teach students math in high school. You are so right about the word problems.
Keski