Acreage Calculator

What is an Acre?

An acre is a unit of land area used in the imperial and US customary systems. It is defined as 43,560 square feet, 4,840 square yards, or about 4,046.86 square meters. Historically, an acre represented the amount of land a yoke of oxen could plow in a single day. Today, it remains the standard unit for measuring real estate, farmland, timberland, and large residential lots in the United States, the United Kingdom, and many other countries that follow imperial measurement conventions.

One acre is roughly equivalent to 90% of an American football field (without the end zones) or a rectangle measuring 208.71 feet by 208.71 feet (a square acre). Understanding acreage is essential for landowners, real estate agents, farmers, surveyors, and anyone involved in land development or property transactions.

How to Calculate Acreage for Different Shapes

Calculating acreage always follows the same approach: compute the area in square feet using the appropriate geometric formula, then divide by 43,560 (the number of square feet in one acre). The calculator above handles all the conversions automatically, but understanding the formulas helps you verify results and plan your measurements.

Rectangle or Square

For rectangular or square parcels, measure the length and width in the same unit and multiply them together to get the area. If your measurements are in feet, the formula is:

$$A\;(sq\;ft) = Length \times Width$$

$$Acres = \frac{Length \times Width}{43{,}560}$$

For example, a rectangular lot measuring 200 feet by 150 feet contains 30,000 square feet, which equals 30,000 ÷ 43,560 ≈ 0.689 acres.

Triangle

Triangular parcels are common on corner lots, irregular subdivisions, and flag lots. Measure the base length and the perpendicular height (the distance from the base to the opposite vertex):

$$A\;(sq\;ft) = \frac{1}{2} \times Base \times Height$$

$$Acres = \frac{Base \times Height}{2 \times 43{,}560}$$

A triangle with a 300-foot base and 200-foot height contains 30,000 square feet, or 0.689 acres.

Circle

Circular parcels occur with center-pivot irrigation fields, round pens, and certain zoning lots. Measure the radius (distance from center to edge) or the diameter (distance across the center):

$$A\;(sq\;ft) = \pi r^2 \quad \text{or} \quad A = \frac{\pi d^2}{4}$$

$$Acres = \frac{\pi r^2}{43{,}560}$$

A circular area with a radius of 100 feet contains about 31,416 square feet, or 31,416 ÷ 43,560 ≈ 0.721 acres.

Common Lot Sizes and Their Acreage

The table below shows typical parcel dimensions and their equivalent acreage. Use it as a quick reference when evaluating property sizes.

Acreage Conversion Reference

If you are planning construction, landscaping, or site development on your property, you may also find our Area Calculator useful for computing areas of any shape, or the Square Footage Calculator for smaller-scale measurements like rooms and floors. The Hectares to Acres Converter helps when working with international property listings, and the Concrete Calculator can estimate the material needed for foundations, slabs, and walkways on your land.

Knowing how acreage relates to other units of area is useful when comparing properties or reading international listings:

• 1 acre = 43,560 square feet
• 1 acre = 4,046.86 square meters
• 1 acre = 0.404686 hectares
• 1 acre = 160 perches (square rods)
• 1 acre = 4,840 square yards
• 1 hectare = 2.47105 acres