Property Size Calculator
Enter your lot's length and width to get total property size in square feet, square meters, and acres.
Last updated:Tip: If you only have the diameter, divide by 2 to get the radius.
L-shape = two rectangles sharing a corner.
Add one row per rectangle and we'll sum them.
Property Size Quick Reference
| Lot Size | Acres | Typical Use |
|---|---|---|
| 5,000 sq ft | 0.11 | Urban lot |
| 8,000 sq ft | 0.18 | Average suburban |
| 10,890 sq ft | 0.25 | Quarter acre |
| 21,780 sq ft | 0.50 | Half acre |
| 43,560 sq ft | 1.00 | One full acre |
| 217,800 sq ft | 5.00 | Small rural parcel |
Conversion: 1 acre = 43,560 sq ft. Need more detail? Use our Square Feet to Acres converter.
Irregular Lot Shapes
Most suburban lots are rectangles, but country lots are rarely regular. Switch to Irregular mode and split your property into rectangles or triangles. A common workflow is:
- Pull your plat or survey from your county records.
- Overlay a grid and split the parcel into rectangles plus one or two right triangles.
- Enter each rectangle in the calculator above. For triangles, use
(base × height) / 2. - Compare the total to the lot size on record — they should agree within a few percent.
Property vs. House Square Footage
These two numbers are often confused in listings and tax records:
- Property / lot size is the entire parcel from the survey corners. This number is used for zoning setbacks and property taxes.
- House square footage is the finished, heated interior of the home. Use the house calculator to measure this.
- Building footprint is the part of the lot covered by the house, measured at ground level.
How Lot Size Affects Value and Use
- Zoning coverage: many US suburbs cap building footprint at 25–40% of lot area.
- Setbacks: a 10,000 sq ft lot may only allow a 5,000 sq ft buildable envelope after setbacks.
- Septic and wells: rural lots usually need at least 1 acre for standard septic systems.
- Landscaping: irrigation cost scales with lot size — not house size.
Acreage Examples You'll Recognize
| Reference | Approx. sq ft | Acres |
|---|---|---|
| NBA basketball court | 4,700 | 0.11 |
| American football field (incl. end zones) | 57,600 | 1.32 |
| Soccer pitch (FIFA) | 77,400 | 1.78 |
| Baseball infield (90 ft basepaths) | 8,100 | 0.19 |
| One acre (1 chain × 10 chains) | 43,560 | 1.00 |
Frequently Asked Questions
How do I calculate property size in square feet?
Multiply lot length by lot width in feet. For irregular lots, split the parcel into rectangles and triangles using a plat or survey, compute each area, and sum the values.
How many square feet are in one acre?
One acre = 43,560 sq ft = 4,046.86 sq m = 4,840 sq yd. Use the sq ft → acres converter for quick math.
What is a quarter acre in square feet?
10,890 sq ft — for example a 99 × 110 ft lot. This is the most common suburban lot size in the US.
How big is a half-acre lot?
21,780 sq ft, roughly a 145 × 150 ft lot. Half-acre lots are common in semi-rural subdivisions and move-up suburbs.
Does property size include the house?
Property or lot size is the entire parcel. House square footage is only the finished living area. Real estate listings usually show both numbers separately.
How do I calculate square footage for an irregular lot?
Break the boundary into rectangles and right triangles using your plat, compute each area, and add them. The irregular-shape tab in the main calculator handles this automatically.