Map Area Calculator
Draw any shape on the map to calculate its area and perimeter. Get instant conversions to square feet, square meters, acres, hectares, and more — plus cost estimates for fencing, sod, concrete, and paving. Works anywhere in the world with geodesic precision.
How to measure area on a map
The map area calculator lets you draw any shape on an interactive map and instantly see the enclosed area in six different units. It works anywhere in the world and uses geodesic calculations that account for Earth's curvature — the same math used by professional GIS software like ArcGIS and QGIS.
What people use area measurement for
1. Estimating property lot size
Before listing a home or making an offer, knowing the exact lot size matters. Zillow and Redfin sometimes show outdated or incorrect lot sizes from county records. Drawing the actual property boundary on a satellite map gives you an independent measurement to verify. This is especially useful when fence lines don't match recorded property boundaries, or when county records haven't been updated after surveys.
2. Calculating roofing material needs
Roofers measure the roof footprint from satellite view to estimate how many squares of shingles they need. One roofing square covers 100 square feet. A 2,000 sq ft roof footprint with a standard 5:12 pitch needs approximately 22 squares after the pitch adjustment. This helps homeowners verify contractor quotes and catch overestimates before signing a contract.
3. Farm field measurement for seed and fertilizer
Farmers calculate field acreage to determine seed quantities, fertilizer rates, and crop insurance coverage. A 40-acre corn field needs approximately 32,000 seeds per acre, and fertilizer is priced per acre. Getting the acreage wrong by even 5% can mean hundreds of dollars in wasted inputs or undertreated sections that reduce yield.
4. Landscaping and lawn care pricing
Lawn care companies price services by square footage. Measuring the actual lawn area (excluding the house, driveway, and garden beds) gives an accurate base for fertilization, aeration, and mowing quotes. A typical suburban lawn is 5,000-8,000 sq ft, but properties vary widely. Getting this number right prevents both underbidding and overcharging.
5. Solar panel installation planning
Solar installers measure usable roof area to determine how many panels will fit. Standard residential panels are about 17.5 sq ft each and produce 350-400 watts. Knowing the exact south-facing roof area (minus obstructions like vents, skylights, and chimneys) determines the maximum system size and expected power output.
6. Outdoor event venue planning
Event planners measure outdoor venues to determine capacity for weddings, festivals, or corporate events. Industry guidelines recommend 8-10 sq ft per guest for standing cocktail events and 12-15 sq ft for seated dinners with tables. Measuring the exact usable area prevents overcommitting on guest counts.
7. Parking lot design and restriping
Property managers and pavement contractors measure parking lots to estimate restriping costs and verify that the lot meets local parking requirements. Standard parking spaces require 162-180 sq ft each (9×18 ft or 9×20 ft), plus drive aisles. Accurate measurements prevent mid-project surprises and ensure zoning compliance.
8. Insurance property assessment
Insurance adjusters and homeowners measure building footprints and land area to verify coverage amounts. Replacement cost insurance is calculated per square foot, so accurate measurements ensure you're neither underinsured (risking inadequate payouts) nor overinsured (paying extra premiums). This is especially important after additions or renovations.
9. Wildlife habitat and hunting land measurement
Land managers and hunters measure property boundaries to calculate wildlife carrying capacity, plan food plots, and verify acreage for hunting leases. Whitetail deer habitat typically supports 1 deer per 10-25 acres depending on region and habitat quality. Accurate acreage is also required for conservation easements and USDA programs.
10. Construction site and excavation planning
Contractors measure building footprints, excavation areas, and concrete pads to estimate material quantities. Concrete is ordered in cubic yards, but calculating the area first is essential. A 4-inch thick slab needs 1.23 cubic yards per 100 sq ft. Accurate area measurements prevent both costly overorders and job-stopping shortages.
Area size reference guide
Use this table to put your measurement in context. If you measured 0.20 acres, that's about the size of an average US home lot. If you measured 1.1 acres, that's roughly one football field.
| Reference | sq ft | sq m | Acres |
|---|---|---|---|
| Average parking space | 162 | 15 | 0.004 |
| Tennis court | 2,808 | 261 | 0.06 |
| Basketball court | 4,700 | 437 | 0.11 |
| Average US home lot | 8,560 | 795 | 0.20 |
| Football field (playing) | 48,000 | 4,459 | 1.10 |
| Soccer field (FIFA) | 76,900 | 7,140 | 1.76 |
| City block (typical) | 100,000 | 9,290 | 2.30 |
| 10-acre farm field | 435,600 | 40,469 | 10 |
| Central Park, NYC | — | — | 843 |
The math behind area calculations
On a flat surface, the area of a polygon is calculated using the Shoelace formula (also called the surveyor's formula or Gauss's area formula): sum the cross products of consecutive vertex coordinates and divide by 2. This method dates back to the 18th century and is still used in land surveying today.
On a curved surface like Earth, flat-plane math introduces errors that grow with area size. This tool uses Turf.js's geodesic area calculation, which projects each triangle of the polygon onto the WGS84 ellipsoid (the same coordinate system used by GPS) and sums the spherical excess. This is the same approach used by professional GIS software like ESRI ArcGIS and QGIS.
For typical residential lots (under 1 acre), the difference between flat-plane and geodesic calculation is negligible — less than 0.001%. For a 100-acre farm at 45°N latitude, flat-plane math would overestimate area by about 0.3%. For very large areas at high latitudes (e.g., measuring Alaska), geodesic calculation is essential.
Area unit conversion reference
Different industries and countries use different area units. Real estate in the US uses square feet and acres. Agriculture uses acres (US) or hectares (metric countries). International standards use square meters and hectares. Here are the key conversions:
| Unit | Square Feet | Square Meters |
|---|---|---|
| 1 acre | 43,560 | 4,047 |
| 1 hectare | 107,639 | 10,000 |
| 1 square mile | 27,878,400 | 2,589,988 |
| 1 square kilometer | 10,763,910 | 1,000,000 |
Quick mental math: 1 acre ≈ 90% of an American football field. 1 hectare ≈ 2.5 acres. 1 square kilometer = 100 hectares = 247 acres.
How cost estimates are calculated
The cost estimates shown in the results panel are based on national average prices from industry sources. Actual costs vary significantly by location, materials, and contractor rates. Use these as rough planning figures, not quotes.
Based on 6-foot wood privacy fence including materials, posts, and labor. Chain link runs $10-15/ft, vinyl $25-40/ft, wrought iron $30-50/ft. Data from HomeAdvisor 2024 national averages.
Includes sod, soil prep, and installation. Bermuda and fescue run lower ($0.35-0.55); St. Augustine and Zoysia run higher ($0.55-0.85). Seed is cheaper at $0.04-0.12/sq ft but takes longer to establish. Source: Angi 2024 landscaping cost guide.
4-inch thick poured concrete slab with basic finish. Stamped or colored concrete adds $4-8/sq ft. Price includes site prep, forms, pouring, and finishing. One cubic yard covers ~81 sq ft at 4 inches thick. Source: Concrete Network 2024 pricing.
2-3 inch asphalt layer on prepared base. Driveway-grade asphalt at the lower end; commercial-grade at the higher end. Includes grading, base layer, and compaction. Asphalt prices fluctuate with oil prices. Source: Fixr 2024 paving cost guide.
Agricultural area reference
Farmers and land managers use acreage to calculate seed quantities, fertilizer rates, and expected yields. The tool shows agricultural estimates for areas over 0.25 acres. Here are the formulas and sources:
| Crop | Seeding Rate | Avg Yield |
|---|---|---|
| Corn | 32,000 seeds/acre | 175 bu/acre |
| Soybeans | 140,000 seeds/acre | 50 bu/acre |
| Winter wheat | 1.2M seeds/acre | 47 bu/acre |
| Hay (alfalfa) | 18-22 lbs/acre | 3.5 tons/acre |
Yields vary widely by region, soil quality, and weather. The figures above are 2023 national averages from the USDA National Agricultural Statistics Service (NASS). Corn yields have increased from 120 bu/acre in 2000 to 175 bu/acre today due to improved seed genetics and farming practices.
Related tools and resources
For circular areas instead of custom shapes, the Map Radius Tool lets you draw a circle of any distance and shows the enclosed area automatically. It's ideal for coverage analysis, delivery zones, and "within X miles" searches.
To measure the straight-line distance between two points rather than an enclosed area, use the Distance Between Two Places calculator. It shows distance in miles, kilometers, and nautical miles with travel time estimates.
If you need to find the population living within a specific area, the Population Within Radius tool combines geographic boundaries with US Census data to estimate the number of people in any circular area.
For precise coordinates of any location, the Latitude & Longitude Finder shows exact GPS coordinates that you can use in surveying software, Google Earth, or coordinate-based navigation systems.
Frequently asked questions
Area and perimeter calculations use Turf.js geodesic functions on the WGS84 ellipsoid. Map tiles from OpenFreeMap with OpenStreetMap data. Address search via Photon. Map rendering by MapLibre GL JS. All calculations run client-side in your browser.