if you have total square footage from a listing or the assessor, divide by 43,560 and that will give you acres.
Measure the field, multiply to find square feet, divide by 43560. Example: Field is 560 x 640. 560 x 640 = 358,400 358,400/43560 = 8.23 acres May The Sheep Be With You
Your local ag/soils office may have an overlay that you could you put over their aerial photo of your property. Or they may already have it broken out in their records if this field is classified by your county as ag land.
I think what you are trying to figure out is an approx. on certain fields. I do this a lot on google earth. I use the measuring device on google earth for measuring field calculations, tree stand placements and even approx. shot distance.
I also bought an app for my Android phone called Area Calculator Pro. I can walk the perimeter and it will calculate the size.
Google Planimeter works well. Just mark points around the area you want to know acreage of and it calculates it. I use it to figure out seed and fertilizer etc. for food plots and ag fields.
Go to "web soil survey". Google it. You can draw a perimeter around a section of a map and it will give you the acreage. It will also give you a distance (for example, an entry or exit route)
