Measure a paddock, pivot circle, or triangular corner in feet, then read acres (and square feet) instantly. One acre = 43,560 sq ft.
Use this when you have a tape, wheel, or GPS length/width for a roughly rectangular field, a triangular wedge, or a circular center-pivot area — and you need acres for seed, fertilizer, stocking, or fence quotes.
For irregular polygons, split the field into rectangles and triangles, run each piece, and add the acres. Survey plats still win for legal boundaries.
Square feet depend on shape. Acres = square feet / 43,560. Circle uses pi approx 3.14159265.
Rectangle: sq_ft = L x W
Triangle: sq_ft = (base x height) / 2
Circle: sq_ft = π x r²
acres = sq_ft / 43,560
This is planar area from your entered dimensions — not a deed acreage, GIS layer, or slope-adjusted surface area.
A square paddock: 660 ft x 660 ft → 435,600 sq ft → 10.00 acres.
Center pivot with radius 1,320 ft (1/4 mile): π x 1,320² ≈ 5,473,893 sq ft → ≈ 125.7 acres.
Assumptions: flat plan-view geometry; inputs in feet; triangle height is perpendicular to the base.
Limits: slopes, curved fence lines, and roads cutting corners need field survey or GIS.
Responsibility: do not use this alone for property lines, easements, or cost-share acre reporting without official measurements.
Exactly 43,560 square feet. A square acre is about 208.71 ft on a side.
This page is feet to acres. Convert meters to feet (x 3.28084) first, or convert m² / 4046.86 for acres.
Compute the full circle, then multiply by the fraction of 360 degrees you irrigate (e.g., 180 degrees → x 0.5).
GPS track area can differ from LxW if boundaries bow. Use this for rough layout; trust surveyed acres for contracts.