🌾 Acreage Calculator
Find the size of any lot or parcel of land in acres — plus square feet, square meters, hectares, square miles, perimeter, and fencing cost. Rectangle, circle, triangle, and trapezoid shapes. Free, no sign-up.
An acreage calculator finds the size of a piece of land — the area enclosed by its boundary. It converts your parcel's dimensions into acres, square feet, square meters, hectares, and square miles, and also gives the perimeter and an estimated fencing cost. The core conversion is:
How to calculate acreage in 3 steps:
- Pick a shape — rectangle, circle, triangle, or trapezoid — and measure the parcel's dimensions in feet.
- Enter the dimensions. For an irregular parcel, split it into simple shapes and total the areas.
- Click Calculate Acreage to see acres, square feet, square meters, hectares, square miles, perimeter, and fencing cost.
For example, a 660 ft × 660 ft parcel is 435,600 square feet ÷ 43,560 = exactly 10 acres. That equals about 40,469 square meters, 4.05 hectares, or 0.0156 square miles, with a 2,640-foot perimeter to fence.
Acreage Calculator
Pick a shape, enter dimensions, see the land size in every unit plus perimeter and fence cost.
Know the True Size of Your Land –
in Acres, Hectares, and Every Other Unit
Acreage is the number behind every land listing, property tax bill, and fencing quote. A parcel is rarely a neat rectangle, and the conversion to acres trips people up. This free calculator turns your boundary measurements into land size in every unit — plus perimeter and fence cost — in seconds.
⚡ Try the Calculator NowAcreage: The Number That Defines a Piece of Land
Whether you are buying a lot, selling a parcel, planning a fence, paying property tax, or just settling a question about how big the backyard really is, it all comes down to one figure: the acreage. And land almost never comes in a tidy rectangle, which is what makes it tricky.
The math itself is simple: find the area in square feet, then divide by 43,560 — the exact number of square feet in an acre. The challenge is that real parcels are irregular. A lot might be a rough rectangle, a corner triangle, or a four-sided shape with no right angles at all. The trick is breaking it into shapes you can measure.
This free Acreage Calculator handles each one. Pick a shape — rectangle, circle, triangle, or trapezoid — enter the boundary dimensions, and it returns the size in acres, square feet, square meters, hectares, and square miles, plus the perimeter and an estimated cost to fence it.
How the Acreage Calculator Works
Pick a shape, enter the boundary dimensions, and click once. The calculator returns the land size in five units plus the perimeter and fencing cost. Here is what each field does.
Pick the Parcel Shape
Rectangle covers standard lots. Triangle covers corner parcels and odd wedges. Circle handles round plots and pivot-irrigation fields. Trapezoid covers four-sided parcels with two parallel boundary lines.
Choose Feet or Meters
Toggle between Imperial and Metric. US deeds and surveys use feet; most other countries use meters. The acreage result is shown regardless of which unit you enter.
📐 Property surveys list boundary lengths you can type straight in.Enter the Boundary Dimensions
For a rectangle, the length and width. For a triangle, the base and perpendicular height. For a trapezoid, the two parallel sides and the distance between them.
📊 An irregular parcel splits into shapes — run each and add them.Enter the Parcel Count
Measuring several identical lots? Enter the count and the calculator totals them. For a single parcel, leave this at 1.
Add a Fence Type (Optional)
Switch to Advanced mode to pick a fence type and price per linear foot. The calculator multiplies it by the perimeter to estimate what fencing the boundary would cost.
Hit Calculate — Read Every Number
Instantly see the size in acres, square feet, square meters, hectares, and square miles, plus the perimeter and an estimated fencing cost across three fence grades.
✅ Formula: Acres = Square Feet ÷ 43,560The Acreage Formula, Explained
There are two parts: find the area in square feet using the right shape formula, then convert to acres with a single division.
The conversion: One acre is exactly 43,560 square feet — a fixed legal definition. So acreage equals the total square footage divided by 43,560. A parcel of 87,120 square feet is 87,120 ÷ 43,560 = exactly 2 acres. That division is the whole conversion; everything else is finding the square footage.
The shape formulas: A rectangle's area is length times width. A triangle's area is half the base times the perpendicular height. A circle's area is π times the radius squared, where the radius is half the diameter. A trapezoid's area is the average of the two parallel sides, times the distance between them — written as (Side A + Side B) ÷ 2 × Height.
Why 43,560: The acre is an old unit, historically the area a team of oxen could plough in a day. It was standardized as one chain by one furlong — 66 feet by 660 feet — which is 43,560 square feet. The number looks arbitrary but it comes straight from those traditional measures, and it has not changed.
Perimeter and fencing: The perimeter is the total distance around the boundary. It is calculated separately from the area because fencing follows the edge, not the enclosed space. Multiplying the perimeter by a price per linear foot gives the fencing cost — which is why two parcels of equal acreage can cost very different amounts to fence.
Land Unit Conversion Tables
A handful of conversions cover almost every land measurement question. The 43,560 and 640 figures are the two worth memorizing.
| Conversion | Factor | When You Use It |
|---|---|---|
| Square feet → acres | ÷ 43,560 | The core acreage calculation |
| Acres → square miles | ÷ 640 | Large rural tracts and sections |
| Acres → hectares | × 0.4047 | Converting to the metric land unit |
| Square feet → square meters | × 0.0929 | Working with metric surveys |
| Acres → square feet | × 43,560 | Going from a listed acreage to area |
The formula in plain language: Find the parcel's area in square feet using its shape, then divide by 43,560 for acres. A 660 × 660 parcel is 435,600 square feet, and 435,600 ÷ 43,560 = exactly 10 acres.
Common Lot Sizes in Acres
| Lot | Square Feet | Acres |
|---|---|---|
| Small city lot (50 × 100) | 5,000 ft² | 0.11 |
| Quarter-acre lot | 10,890 ft² | 0.25 |
| Half-acre lot | 21,780 ft² | 0.50 |
| One full acre | 43,560 ft² | 1.00 |
| Football field (with end zones) | 57,600 ft² | 1.32 |
Acreage Reference Points
| Area | Size | Useful As |
|---|---|---|
| 1 acre | 43,560 ft² | The base land unit |
| 1 acre, if square | ~208.7 ft per side | Picturing an acre on the ground |
| 1 hectare | 2.47 acres | The metric land unit |
| 1 square mile (section) | 640 acres | Rural land surveying |
| Quarter section | 160 acres | A common large parcel |
An acre has no fixed shape. It can be a near-square of about 209 feet per side, or a long, narrow strip — both are one acre as long as the area totals 43,560 square feet.
Factors That Affect an Acreage Estimate
A formula gives a precise number from the inputs you provide. Whether that number matches the real parcel depends on these factors.
The Four Parcel Shapes Compared
This calculator offers four shapes. Choosing the one that best fits the parcel — or splitting the parcel between several — is what makes the acreage accurate.
| Shape | Best For | What to Measure | Watch Out For |
|---|---|---|---|
| Rectangle | Standard lots, fields with square corners | Length and width of the boundary | Real lots are rarely perfectly square |
| Triangle | Corner parcels; splitting irregular land | Base and the perpendicular height to it | Height must meet the base at a right angle |
| Circle | Pivot-irrigation fields, round plots | Diameter across the widest point | Uncommon for legal parcels |
| Trapezoid | Four-sided lots with two parallel lines | Both parallel sides and the gap between | Needs two genuinely parallel boundaries |
How to Measure a Parcel: A Phase-by-Phase Roadmap
Getting a reliable acreage figure is a short process. Here are the four phases from a vague idea of lot size to a number you can plan around.
Before measuring anything, check the property deed, any existing survey, or the county plat map. These often list boundary lengths directly. A recorded survey is the most reliable source — if you have one, the numbers are already there.
Sketch the lot roughly to scale and divide it into rectangles, triangles, and trapezoids that follow the real boundary. Label each piece. This sketch is the plan for every measurement and calculation that follows.
Measure the boundary lengths with a long tape, a measuring wheel, or mapping tools. For each shape in your sketch, capture the dimensions its formula needs. The more careful the measurement, the more trustworthy the acreage.
Enter each shape's dimensions, calculate its acreage, and add the pieces for the parcel total. For anything legal — a sale, a subdivision, a boundary line — take this working figure to a licensed surveyor for an authoritative measurement.
2026 Land Fencing Cost Breakdown
The most common cost tied to acreage is fencing — and fencing follows the perimeter, not the area. Here is what it runs in 2026.
The calculator's fence estimate multiplies your parcel's perimeter by a price per linear foot. Because cost scales with the boundary length, a long, narrow parcel costs far more to fence than a square one of the same acreage. The fence type sets the price; the table below shows 2026 ranges.
| Parcel | Approx. Perimeter | Wire Fence | Wood Privacy |
|---|---|---|---|
| Quarter acre (square) | ~417 ft | $850–$2,100 | $8,300–$14,600 |
| One acre (square) | ~835 ft | $1,700–$4,200 | $16,700–$29,200 |
| Five acres (square) | ~1,867 ft | $3,700–$9,300 | $37,300–$65,300 |
| Ten acres (660 × 660) | 2,640 ft | $5,300–$13,200 | $52,800–$92,400 |
| One acre (long strip) | ~1,400 ft | $2,800–$7,000 | $28,000–$49,000 |
Example Acreage Calculations
Three parcels, three shapes — all worked through with verified math so you can sanity-check your own results.
Getting the Most From an Acreage Figure
An accurate acreage number is useful well beyond satisfying curiosity. These six habits make the figure more reliable and more valuable.
The single most important habit is splitting irregular land into well-fitted shapes. A parcel approximated as one rough rectangle can be off by a wide margin; the same parcel divided into two or three pieces that follow the real boundary is usually accurate to within a few percent. The calculator makes running several shapes quick.
The second habit is knowing when an estimate is enough and when it is not. For planning a fence, picturing a lot, or comparing listings, a careful calculator estimate is fine. For a sale, a subdivision, a mortgage, or a boundary dispute, only a licensed surveyor's figure carries legal weight.
Six Practical Habits
When This Calculator Is the Wrong Tool
The geometry is exact, but acreage in the real world has limits a calculator cannot cross. Here is where the output needs care.
1. Legal and transactional use. This tool gives a working estimate, not a legal measurement. A property sale, a subdivision, a mortgage, or a boundary dispute requires a licensed surveyor whose figure carries legal authority. Never rely on a calculator estimate for a binding decision.
2. Genuinely curved boundaries. Parcels bounded by winding roads or rivers have edges no straight-sided shape captures exactly. Approximating with segments gets close, but the result is always an estimate — and the more the boundary curves, the larger the uncertainty.
3. Total acreage vs usable acreage. The calculator finds the area inside the boundary. It does not know which parts are wetland, easement, steep slope, or setback. A parcel's deed acreage and its buildable acreage can differ substantially.
4. Sloped-land surface area. Acreage is the flat, horizontal footprint, which is how land is legally recorded. If you need the actual surface area of a steep hillside — for some agricultural or construction purposes — that is a different and larger figure than the recorded acreage.
Where to go instead: For room and project areas measured in square feet, a square footage calculator is the natural fit. For ordering bulk material by depth across an area, a cubic yard calculator handles the volume. This tool's strength is land — turning parcel boundaries into acres, hectares, and fencing cost.
Land Terms You'll See On This Page
Quick reference for the land and measurement terms used throughout this calculator.
- Acre
- A unit of land area equal to exactly 43,560 square feet. It has no required shape — only a fixed area.
- Acreage
- The size of a piece of land expressed in acres. The headline figure this calculator produces.
- Hectare
- The metric unit of land area, equal to 10,000 square meters or about 2.47 acres.
- Square Mile
- An area one mile on each side, equal to 640 acres. Also called a section in US land surveying.
- Section
- A one-square-mile block of 640 acres, the basic unit of the US public land survey system.
- Quarter Section
- One quarter of a section — 160 acres — a common size for a large rural parcel.
- Perimeter
- The total distance around a parcel's boundary. It determines fencing cost, separate from the acreage.
- Parcel
- A defined piece of land with set boundaries, identified as a single property unit.
- Plat Map
- A recorded map showing how land is divided into parcels, with boundary dimensions and lot lines.
- Deed
- The legal document that transfers and describes a property, usually including a boundary description.
- Survey
- A precise, professional measurement of a property's boundaries and area, carried out by a licensed surveyor.
- Trapezoid
- A four-sided shape with two parallel sides. Its area is the average of those sides times the distance between them.
- Easement
- A right for someone to use part of a parcel — for a road or utilities. It lies within the acreage but limits its use.
- Frontage
- The length of a parcel's boundary along a road or other feature — often one of the parallel sides of a trapezoidal lot.
Frequently Asked Questions
The most common questions about calculating acreage and land size.
How do I calculate acreage?
Find the area in square feet — for a rectangle, multiply length by width — then divide by 43,560, the number of square feet in one acre. A lot 300 feet by 200 feet is 60,000 square feet, and 60,000 ÷ 43,560 ≈ 1.38 acres. For irregular land, split it into rectangles and triangles, find each area, and add them. This calculator does every step automatically.
How many square feet are in an acre?
There are exactly 43,560 square feet in one acre. This is a fixed legal definition, not an approximation. To convert square feet to acres, divide by 43,560; to convert acres to square feet, multiply by 43,560. An acre has no required shape — it is simply any area totaling 43,560 square feet.
How big is an acre?
An acre is 43,560 square feet. If it were a perfect square, each side would be about 208.7 feet. For comparison, an American football field including both end zones is about 1.32 acres, so one acre is a little smaller than a football field. An acre can be any shape — long and narrow or square — as long as the total area is 43,560 square feet.
How do I calculate the acreage of an irregular lot?
Break the lot into simple shapes — rectangles, triangles, and trapezoids — that together cover the whole parcel. Calculate the area of each piece, add them for the total square footage, then divide by 43,560 for acres. This calculator lets you switch shapes and run each section in turn; the trapezoid shape is especially useful for four-sided parcels with two parallel boundaries.
How many acres is a 100 x 100 lot?
A lot measuring 100 feet by 100 feet is 10,000 square feet. Dividing by 43,560 gives about 0.23 acres — just under a quarter of an acre. A quarter-acre lot, a common suburban size, is 10,890 square feet, so a 100-by-100 lot is slightly smaller than a quarter acre.
How do I convert acres to hectares?
Multiply acres by 0.4047 to get hectares. To convert the other way, multiply hectares by 2.471 to get acres. For example, 10 acres is 10 × 0.4047 = 4.047 hectares. The acre is the customary land unit in the United States, while the hectare is the metric unit used in most other countries.
How many acres are in a square mile?
There are 640 acres in one square mile. This is why land in much of the US is divided into one-square-mile sections of 640 acres, with a quarter section being 160 acres. To convert square miles to acres, multiply by 640; to convert acres to square miles, divide by 640.
How do I calculate acreage from a survey?
A survey lists the boundary lines with their lengths and directions. The simplest approach is to plot the corners and divide the parcel into rectangles and triangles whose dimensions you can read from the survey, then total their areas and convert to acres. For legally precise acreage, surveyors use a coordinate method, but splitting into simple shapes gives a reliable working estimate.
How much does it cost to fence an acre?
Fencing cost depends on the perimeter, not the acreage, and a square acre has a perimeter of about 835 feet. At that perimeter, wire or field fencing at $2–$5 per linear foot runs roughly $1,700–$4,200; chain-link at $10–$20 per foot runs $8,000–$17,000; and wood privacy fencing at $20–$35 per foot runs $17,000–$29,000. A long, narrow acre has a much larger perimeter and costs more to fence than a square one.
Why does the shape of a parcel affect fencing cost but not acreage?
Acreage measures the area enclosed, while fencing follows the perimeter — the distance around the edge. Two parcels can both be exactly one acre but have very different perimeters: a square acre has a perimeter near 835 feet, while a long, narrow one-acre strip can have a perimeter several times longer. More perimeter means more fence, so shape drives fencing cost even when the acreage is identical.
What is a perch, rood, or other old land unit?
These are historical land units still seen in older deeds. A perch, also called a rod or pole, is 16.5 feet; a square perch is 272.25 square feet. A rood is a quarter of an acre, or 10,890 square feet. Forty square perches make one rood, and four roods make one acre. Modern calculators work in acres and square feet, but these older units still appear in long-standing property records.
How accurate is an acreage estimate from measurements?
An acreage estimate is only as accurate as the boundary measurements and the shapes used to approximate the parcel. Measuring carefully and splitting irregular land into well-fitted rectangles and triangles gives a good working figure. However, for a property sale, a legal boundary dispute, or a permit, only a licensed surveyor's measurement is authoritative. Use a calculator estimate for planning, not for legal purposes.
More Tools You'll Love
Acreage is one way to measure land and space. These companion calculators handle the related measurements.
Find the Size of Any Parcel
in 30 Seconds
Pick a shape, enter your boundary dimensions — get the land size in acres, square feet, square meters, hectares, and square miles, plus perimeter and fence cost. All free.
Calculate Acreage — Free Takes 30 seconds · No account needed · 4 parcel shapes