Acreage Calculator: Convert Land Dimensions to Acres

An acreage calculator estimates the area of a plot and expresses it in acres from dimensions you enter. Enter the land’s length and width in the same unit; the calculator returns the area in acres and square feet, using a rectangular-plot assumption.

Formula

For a rectangular parcel, area equals length multiplied by width. To convert square feet to acres, divide by 43,560 square feet per acre.

• Length (l): one side of the plot, in feet.
• Width (w): the perpendicular side, in feet.
• Area in acres: l × w ÷ 43,560.
• Area in square feet: l × w.

The standard acre is 43,560 square feet, or 4,840 square yards, or 4,046.8564224 square metres. An acre is a unit of area, not a fixed shape: a square acre would be about 208.71 feet on each side, but a long, narrow parcel can have the same area.

Worked Example

Using the calculator’s default dimensions, length is 660 feet and width is 66 feet.

1. Multiply the dimensions: 660 ft × 66 ft = 43,560 sq ft.
2. Convert square feet to acres: 43,560 ÷ 43,560 = 1.00 acre.
3. The square-foot output is 43,560 sq ft.

The displayed acreage is rounded to two decimal places. Here the exact result is one acre, so rounding does not change it.

What an Acreage Calculator Is For

An acreage calculator is a quick way to estimate land area from measurements, or to convert a known area into a familiar unit. It can help with a garden, lawn, building site, field, or other plot when you have reliable dimensions. It does not measure the land itself or verify boundary lines; the result is only as dependable as the measurements and shape assumptions you provide.

For a rectangular plot, measure the length and width in feet and enter both. If your measurements are in yards, metres, or another unit, convert them consistently first or calculate the area in that unit and use the appropriate conversion. Mixing feet and yards in one multiplication produces a meaningless result.

For example, a 100-foot-by-200-foot rectangle has an area of 20,000 square feet. Dividing by 43,560 gives about 0.46 acre. That is a useful estimate, but it does not mean the parcel is close to a square: area describes how much surface there is, not its shape or dimensions.

When the Plot Is Not a Rectangle

Many parcels have angled, curved, or irregular boundaries. Multiplying the longest length by the widest width usually calculates the area of a containing rectangle, not the actual parcel, and can overstate acreage. Break a shape into smaller pieces that can be measured more reliably, calculate each piece’s area, then add the results.

• Rectangles: calculate each length × width and add the areas.
• Right triangles: calculate base × perpendicular height ÷ 2.
• Trapezoids: calculate (parallel side A + parallel side B) × perpendicular height ÷ 2.

Convert all component areas to the same unit before adding. If the boundary is highly irregular, measurements come from a map, or the result matters for a purchase, construction, or boundary decision, a survey or appropriate mapping method is more suitable than a simple dimensions calculator.

Units, Precision, and Common Errors

One acre equals 43,560 square feet, 4,840 square yards, and approximately 0.404686 hectare. In metric units, multiply square metres by about 0.000247105 to get acres, or divide acres by about 0.000247105 to get square metres. For instance, 1,000 square metres is approximately 0.247 acre.

A frequent mistake is confusing a linear unit with a square unit. A 10-foot length is not an area; multiplying 10 feet by 10 feet gives 100 square feet. Another is treating an acre as a fixed-length measurement. Because parcels can have many shapes, “one acre” alone does not specify the dimensions.

Rounding can matter when a plot is small or measurements are approximate. Keep unrounded intermediate values where possible, then round the final acreage to a sensible number of decimal places. More digits do not make uncertain measurements more accurate. Sloped ground can also have a greater surface area than its horizontal map footprint; the relevant area depends on what is being measured.

Frequently Asked Questions

How many square feet are in an acre?
An acre contains exactly 43,560 square feet. To convert square feet to acres, divide by 43,560.

How do I calculate acres from length and width?
For a rectangular plot measured in feet, multiply length by width to get square feet, then divide by 43,560. Measure both sides in the same unit.

How many acres is a 100-by-200-foot lot?
Its rectangular area is 20,000 square feet. Dividing by 43,560 gives about 0.459 acre, or 0.46 acre rounded to two decimal places.

How do I calculate acreage in metres?
Multiply length in metres by width in metres to get square metres, then multiply by approximately 0.000247105 to convert to acres. For an irregular plot, account for its shape rather than using only its maximum dimensions.

Can I use this calculator for an irregular property?
Not by entering only its overall length and width: that gives the area of a rectangle. Divide the parcel into measurable shapes and add their areas, or use reliable mapped or surveyed area data.

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in l | Length | ft | 660 | 0
in w | Width | ft | 66 | 0
out acres | Area | acres | l * w / 43560 | 2
out sqft | Area | sq ft | l * w | 0