Field Area Calculator

Calculate field area for farms, pasture, gardens, crop ground, and open land. Estimate acres, hectares, square feet, perimeter, fence length, seed needs, fertilizer needs, yield, crop value, and field value.

Calculate Field Area

Field Area = Length × Width. Acres = Square Feet ÷ 43,560.
Your result will appear here.

How the field area calculator works

Rectangular field mode:
The calculator multiplies field length by field width, then converts square feet into acres, hectares, and other units.

Multiple fields mode:
The calculator multiplies one field area by the number of same-size fields.

Known area mode:
The calculator starts from your known field area and converts it into acres, square feet, hectares, and square miles.

Circular field mode:
The calculator uses diameter to estimate circular field area and boundary length.

Why use a field area calculator?

A field area calculator helps estimate crop field size, farm acreage, pasture area, hay field area, garden field area, irrigation area, and open land measurements.

It can help calculate acres, usable acres, hectares, square feet, square miles, perimeter, fence length, seed needs, fertilizer needs, yield, crop value, and field value.

What your result means

Your result shows gross field area, excluded area, net acres, usable acres, hectares, square feet, square miles, perimeter, fence length, seed needed, fertilizer needed, estimated yield, crop value, and field value.

Field area formulas

Frequently asked questions

How do I calculate field acres?

Calculate the field area in square feet, then divide by 43,560. For a rectangular field, multiply length by width first.

How many square feet are in an acre?

One acre equals 43,560 square feet.

What are usable acres?

Usable acres are the acres available for planting, grazing, or production after accounting for efficiency, headlands, waterways, lanes, wet spots, and excluded areas.

How do I estimate seed needed for a field?

Multiply usable acres by your seed rate per acre. The calculator lets you use pounds, kilograms, seeds, bags, or other units.

Is this field area calculator exact?

No. It is an estimate. Actual field area can vary by survey boundaries, irregular edges, waterways, slopes, headlands, roads, wet spots, excluded areas, and field mapping data.