Backyard Area Calculator
Find the total area of your backyard in square feet, square yards, square metres and acres. Then subtract the space your house, patio or shed already uses to see how much is left to plan.
Areas already used
Add your house, patio, shed or pool. Enter each one in the unit chosen above.
7.5% of your yard is used
The areas you added are larger than the yard. Please check your measurements.
| Unit | Total | Free |
|---|---|---|
| Square feet | 0 | 0 |
| Square yards | 0 | 0 |
| Square metres | 0 | 0 |
| Acres | 0 | 0 |
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How Backyard Area Calculator Works
Four quick steps happen behind the screen every time you change a number.
Reads your measurements
You choose a unit and enter the sides of your yard. Everything is handled in that one unit, so nothing gets mixed up.
Applies the shape formula
The calculator uses the standard area formula for the shape you picked, such as length times width for a rectangle.
Subtracts the space used
Each area you add, like a patio or shed, is removed from the total, so you see the free space left to plan.
Converts the result
Totals appear in square feet, square yards, square metres and acres, ready to compare with product sizes.
How to Use Backyard Area Calculator
Five quick steps take you from a tape measure to a usable area number.
- Pick your unitChoose feet, yards or metres to match how you measured.
- Choose the yard shapeSelect rectangle, triangle, circle or trapezoid and enter its sides.
- Add areas already usedList your house, patio, shed or pool so they are subtracted.
- Read the resultsSee total, used and free area in square feet, yards, metres and acres.
- Plan the next stepTake the free area to our gravel, sod or topsoil calculators.
Formula Used in Backyard Area Calculator
These are the standard area formulas behind every result, so you can check the numbers yourself.
Rectangle
L is length and W is width.
Triangle
b is the base and h is the height.
Circle
r is the radius, and π is about 3.1416.
Trapezoid
a and b are the parallel sides, h is the height.
Free area
Used is the sum of every area you add.
Unit conversion
1 sq yd = 9 sq ft, and 1 sq m = 10.7639 sq ft.
Worked example
A 60 ft by 40 ft yard has 60 × 40 = 2,400 sq ft. A 15 ft by 12 ft patio uses 15 × 12 = 180 sq ft. The free area is 2,400 - 180 = 2,220 sq ft, which is about 0.0510 acres.
Backyard Area Chart
Find the area of a common yard size at a glance. Each row is length times width, shown in four units.
| Yard size | Sq ft | Sq yd | Sq m | Acres |
|---|---|---|---|---|
| 20 × 20 ft | 400 | 44.4 | 37.2 | 0.0092 |
| 25 × 25 ft | 625 | 69.4 | 58.1 | 0.0143 |
| 30 × 30 ft | 900 | 100 | 83.6 | 0.0207 |
| 40 × 30 ft | 1,200 | 133.3 | 111.5 | 0.0275 |
| 40 × 40 ft | 1,600 | 177.8 | 148.6 | 0.0367 |
| 50 × 30 ft | 1,500 | 166.7 | 139.4 | 0.0344 |
| 50 × 50 ft | 2,500 | 277.8 | 232.3 | 0.0574 |
| 60 × 40 ft | 2,400 | 266.7 | 223 | 0.0551 |
| 70 × 50 ft | 3,500 | 388.9 | 325.2 | 0.0803 |
| 80 × 60 ft | 4,800 | 533.3 | 445.9 | 0.1102 |
| 100 × 50 ft | 5,000 | 555.6 | 464.5 | 0.1148 |
| 100 × 100 ft | 10,000 | 1,111.1 | 929 | 0.2296 |
Square Feet Conversion Chart
| Area | Sq yd | Sq m | Acres |
|---|---|---|---|
| 500 sq ft | 55.6 | 46.5 | 0.0115 |
| 1,000 sq ft | 111.1 | 92.9 | 0.0230 |
| 2,000 sq ft | 222.2 | 185.8 | 0.0459 |
| 5,000 sq ft | 555.6 | 464.5 | 0.1148 |
| 10,000 sq ft | 1,111.1 | 929 | 0.2296 |
| 21,780 sq ft | 2,420 | 2,023.4 | 0.5000 |
| 43,560 sq ft | 4,840 | 4,046.9 | 1.0000 |
Values are rounded. One square yard is 9 square feet, one square metre is 10.7639 square feet and one acre is 43,560 square feet.
Common Backyard Area Mistakes
Four slips that throw off the number, and how to avoid them.
Mixing units
Measuring one side in feet and the other in yards gives a wrong area. Pick one unit first, then enter every side in it.
Forgetting used space
The house, patio, shed and pool take room. Add them under areas already used, so the free area is real.
Treating an odd yard as a rectangle
A curved or angled yard is not length times width. Split it into simple shapes and add the areas.
Skipping a waste allowance
When you buy sod, mulch or pavers from this area, add 5 to 10 percent for cuts and uneven ground.
Tools You Must Know
One number is rarely enough for a yard project. These calculators pair well with this one.
Backyard Area Calculator FAQs
Quick answers about measuring and planning your yard.

How do I calculate the area of my backyard?
Multiply length by width for a rectangle. For other shapes, pick the shape in the calculator and enter its sides to get the area.
What units does the Backyard Area Calculator use?
You can enter feet, yards or metres. Results show square feet, square yards, square metres and acres.
How do I find the usable area of my backyard?
Add the house, patio, shed or pool under Areas already used. The calculator subtracts them from the total to show your free area.
How many square feet are in an acre?
One acre is 43,560 square feet.
My backyard is not a perfect rectangle. What should I do?
Split the yard into a few simple shapes and calculate each one, then add the totals. For a quick figure, pick the shape closest to your yard and adjust with the areas you subtract.
Is the Backyard Area Calculator free?
Yes. It is free to use, with no signup.
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