Acreage Calculator
Acres from a lot's length and width — rectangle, trapezoid, triangle or round.
How many acres is my lot? Enter its dimensions in feet, yards or meters. The calculator works out the area, converts it to acres at 43,560 sq ft per acre, and shows square feet, square yards, hectares, the size of a square with the same area and — for a rectangle or circle — the perimeter you would fence.
Calculation Results
An acre is an area, not a shape: 43,560 sq ft can be 208.7 ft square, 330 × 132 ft, or a 1 × 43,560 ft strip.
📱 More free Android calculators
Fencing, decking and drywall estimators from Dixon App Studio — all free on Google Play.
Smart Fencing CalculatorThis site
Fence posts, pickets, rails, concrete, gates and total project cost.
Get it on Google PlaySmart Decking Calculator
Deck boards, joists, footings, railings and material cost estimates.
Get it on Google PlaySmart Drywall Calculator
Drywall sheets, mud, tape, screws and finishing cost estimates.
Get it on Google PlaySod Calculator: Mulch, Topsoil
Sod pallets, mulch, topsoil and seed for the yard around your new fence.
Get it on Google PlayGravel & Stone Calculator
Gravel, crushed stone and base rock in tons and cubic yards.
Get it on Google Play🔧 Recommended Fencing Tools & Supplies
Disclosure: As an Amazon Associate I earn from qualifying purchases.
VEVOR Post Hole Digger,52cc 1450W Auger Digger,Gas Powered Earth Digger with Two Drill Bit 6''& 10''and 3 Extension Rods,for Farmland,Garden and Plant,EPA Certification,Black+Orange+White
$159.90
Check price on Amazon
H.B. Fuller Fast 2K Post Anchor Mix | Expanding Composite Footing Compound (Fence, 1)
$27.99
Check price on Amazon
Ready Seal Exterior Wood Stain | Semi-Transparent Oil-Based Formula | Professional Grade Stain and Sealer in One | Ideal for Decks, Fences, Pergolas, Wood Siding & More | Gallon | Dark Walnut
$39.99
Check price on AmazonPrices as of Oct 1, 2026, 4:36 AM UTC. Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
🛠️ How This Calculator Works
The lot's area is worked out in square feet from its shape — length × width for a rectangle, the average of the two parallel sides × the depth for a trapezoid, base × height ÷ 2 for a triangle, π × diameter² ÷ 4 for a circle — then divided by 43,560 square feet per acre (NIST Handbook 44). Yards and meters are converted to feet first (1 yd = 3 ft, 1 ft = 0.3048 m).
📐 Formula
Acres = area (sq ft) ÷ 43,560 · Rectangle: L × W · Trapezoid: (A + B) ÷ 2 × D · Triangle: B × H ÷ 2 · Circle: π d² ÷ 4 · Hectares = acres × 0.40468564224📝 Example Calculation
A 330 × 132 ft lot: Area = 330 × 132 = 43,560 sq ft Acres = 43,560 ÷ 43,560 = 1.000 acre (0.4047 ha) Perimeter = 2 × (330 + 132) = 924 ft A 100 × 200 ft lot = 20,000 sq ft = 0.459 acres
💡 Pro Tips from Fence Builders
- Take the dimensions from your plat or deed rather than pacing them out — a survey is the only legal measure of a lot.
- Split an irregular lot into rectangles and triangles, run each one, and add the acres.
- A lot with a curved or angled street side is often a trapezoid: measure the two parallel sides and the depth between them.
- Fencing it? A square encloses an area with the least fence; long narrow lots need more linear feet per acre.
- Measured in meters? Pick meters — hectares and square meters are shown too.
Acres for common lot sizes
| Lot (ft) | Square feet | Acres | Perimeter |
|---|---|---|---|
| 50 × 100 | 5,000 | 0.115 | 300 ft |
| 60 × 120 | 7,200 | 0.165 | 360 ft |
| 75 × 150 | 11,250 | 0.258 | 450 ft |
| 100 × 100 | 10,000 | 0.23 | 400 ft |
| 100 × 200 | 20,000 | 0.459 | 600 ft |
| 150 × 300 | 45,000 | 1.033 | 900 ft |
| 208.71 × 208.71 | 43,560 | 1 | 835 ft |
| 330 × 132 | 43,560 | 1 | 924 ft |
| 330 × 660 | 217,800 | 5 | 1,980 ft |
| 660 × 660 | 435,600 | 10 | 2,640 ft |
What an acre is
An acre is a unit of area: 43,560 square feet exactly, which NIST Handbook 44 also lists as 160 square rods, 10 square chains or 0.404 685 642 24 hectare. A square mile is 640 acres. Because it is an area, an acre has no fixed shape — a 330 × 132 ft lot and a 660 × 66 ft strip are both exactly one acre, but the strip needs 1,452 ft of fence to the square lot's 924 ft.
From acres to fence
Know the acreage and need the fence length instead? The acreage to linear feet calculator turns acres into a perimeter for a square or rectangular lot, and the cost to fence an acre page prices it. For livestock fence, count posts with the T-post calculator and wire with the woven wire fence calculator.
❓ Frequently Asked Questions
How do I calculate acreage?
Work out the area in square feet and divide by 43,560, the number of square feet in an acre (NIST Handbook 44). A 150 × 300 ft lot is 45,000 sq ft, or 1.03 acres.
How many square feet are in an acre?
43,560 square feet exactly — 4,840 square yards, or about 4,047 square meters (0.4047 hectare). As a square, an acre is about 208.7 ft on each side.
What are the dimensions of 1 acre?
Any shape with 43,560 sq ft. Common ones: 208.71 × 208.71 ft (square), 330 × 132 ft, 660 × 66 ft (a furlong by a chain, the historic acre), or 100 × 435.6 ft.
How many acres is a 100 by 200 foot lot?
0.459 acres: 100 × 200 = 20,000 sq ft, and 20,000 ÷ 43,560 = 0.459. That is a little under half an acre.
How do I find the acreage of an irregular lot?
Divide it into rectangles, trapezoids and triangles, work each area in square feet, add them, and divide by 43,560. A trapezoid's area is the average of its two parallel sides times the distance between them.
📬 Free Fencing Cost Guide
Get weekly fencing tips, material cost updates, and exclusive calculator guides — straight to your inbox.
No spam, ever. Unsubscribe anytime.
📝 Related Articles
🧮 You May Also Need
Related calculators for your fencing project
