Acreage Calculator

Acreage calculator: length × width ÷ 43,560

This acreage calculator turns a lot’s length and width in feet into acres with one formula: acres = (length × width) ÷ 43,560. An acre is a fixed amount of area, 43,560 square feet, whatever shape the land is. Enter the two side lengths of a rectangular parcel, and the tool returns the acreage to two decimals. If you add a per-acre price, it also multiplies out a cost.

What the formula is doing

There are only two steps. First, length times width gives the area in square feet. Second, dividing by 43,560 tells you how many whole acres fit inside that area. A result of 0.50 means half an acre, or 21,780 sq ft.

The price field is optional. Whatever you type there is treated as dollars per acre, so the cost line is acres × price. That suits per-acre quotes for brush clearing or seeding.

Worked examples

1. The default 300 × 200 ft lot

• Area: 300 × 200 = 60,000 sq ft
• Acres: 60,000 ÷ 43,560 = 1.377, shown as 1.38 acres
• Price left at $0, so cost reads $0.00

2. A long 660 × 330 ft field priced for clearing at $8,000 per acre

• Area: 660 × 330 = 217,800 sq ft
• Acres: 217,800 ÷ 43,560 = 5.00 acres
• Cost: 5.00 × $8,000 = $40,000.00

The second example lands on a round number because 660 ft is one furlong; 660 × 66 ft is exactly one acre, and 330 ft is five chains.

Acreage reference table

Lot size (ft)	Square feet	Acres
50 × 100	5,000	0.11
100 × 150	15,000	0.34
100 × 217.8	21,780	0.50
208.7 × 208.7	43,560	1.00
300 × 200	60,000	1.38
435.6 × 500	217,800	5.00
660 × 660	435,600	10.00
1,320 × 1,320	1,742,400	40.00

Other useful equivalents: 1 acre = 4,840 square yards = about 4,047 square meters = 0.405 hectares. A square mile holds 640 acres.

How to measure a lot for acreage

• Start with paperwork. A deed, plat, or county GIS map usually lists boundary lengths in feet. Those numbers beat a tape measure.
• Measure along the boundary, not the road. Frontage is only one side. You need the depth too.
• Convert other units first. Rods are 16.5 ft, chains are 66 ft, and meters are 3.281 ft. Change everything to feet before entering it.
• Break up odd shapes. An L-shaped yard is two rectangles. A wedge is a rectangle plus a triangle (base × height ÷ 2). Run each rectangle here, work the triangles by hand, add the square feet, then divide by 43,560.
• Use a GPS app for rough rural parcels. Walking the perimeter with a mapping app gets you close, but it is an estimate, not a survey.

Acres, frontage, and what you can actually use

Two lots with the same acreage can feel very different. A 1-acre lot that is 100 ft wide and 435.6 ft deep has narrow frontage and a long backyard. A square acre is about 208.7 ft on each side. Zoning rules often set both a minimum lot area and a minimum frontage, so check both numbers before you buy.

Deeded acreage also counts land you may not be able to use. Wetlands, steep slopes, setbacks, and easements are all inside the boundary. For planning work such as mowing, seeding, or clearing, measure only the part you will treat and run that through the calculator separately.

Common acreage mistakes

• Mixing meters and feet. Entering 100 m as 100 ft understates the area by a factor of about 10.8, since a square meter is 10.76 sq ft.
• Treating a trapezoid as a rectangle. If the back line is shorter than the front, average the two widths before multiplying, or split off the triangle.
• Using “usable” acreage for pricing. Ponds, steep banks, and easements still count toward deeded acres, even though you cannot build on them.
• Rounding too early. 0.34 acres sounds small, but at a per-acre rate the rounding can shift a quote. Keep the square footage if precision matters.
• Relying on a field measurement for a legal question. Boundary disputes, sales, and subdivisions need a licensed surveyor.

Related calculators

To go the other way, use the acres to square feet calculator, or check a smaller area with the square feet to acres calculator. Once you know the size, the grass seed calculator and the land clearing cost calculator turn acreage into material and budget figures.