Lawn Area Calculator
Measure a lawn of almost any shape by adding up a rectangle, a circle and a triangle, then subtracting beds, paths or a patio. Get the lawn area plus the turf rolls, sod pallets or grass seed you need.
Calculate lawn area
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0 if nonem
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Lawn area formulas
| Shape | Area |
|---|---|
| Rectangle or square | length × width |
| Circle | π × (diameter ÷ 2)² |
| Triangle | base × height ÷ 2 |
| Quarter circle (corner bed) | π × radius² ÷ 4 |
Total lawn
Lawn = rectangle + circle + triangle − excluded areasWorked example
10 × 6 m lawn with a 3 m round area added
- Rectangle = 60 m²; circle = π × 1.5² = 7.07 m²
- Lawn = 67.07 m²
- Turf +5% = 71 rolls of 1 m²; seed for a new lawn = 67.07 × 35 g = 2.35 kg
Turf and seed rates
| Item | Metric | Imperial |
|---|---|---|
| Turf roll (UK) | 1 m² per roll | ≈ 10.8 ft² |
| Sod piece (US) | ≈ 0.25 m² | 16 × 24 in = 2.67 ft² |
| Sod pallet (US) | ≈ 42–46 m² | 450–500 ft² |
| Seed, new lawn | 35 g/m² | ≈ 7 lb per 1,000 ft² |
| Seed, overseeding | 20 g/m² | ≈ 4 lb per 1,000 ft² |
Seed rates vary by grass mix; tall fescue and ryegrass blends are often sown more heavily than fine fescue. Follow the rate on the bag.
Measuring an irregular lawn
- Find the biggest rectangle that fits inside the lawn and measure it.
- Add the leftovers as circles, half-circles or triangles. For a curved edge, a triangle from the rectangle’s corner to the furthest point is a good approximation.
- Subtract features such as beds, trees with surrounds and paving.
- Add 5–10% to turf orders for cutting around curves.
Frequently asked questions
How do I measure the area of my lawn?
Split it into simple shapes, calculate each one and add them together, then subtract anything that isn’t grass.
How much turf do I need?
Your lawn area plus about 5% for straight edges, or 10% for curved borders. Turf is sold by the square metre roll in the UK.
How much grass seed per square metre?
About 35 g/m² for a new lawn and 15–25 g/m² for overseeding an existing one.
Related calculators
Garden Soil CalculatorTopsoil under new turf
Mulch CalculatorMulch for the borders
Room Area CalculatorOther area tools
Results are estimates. Lay turf within 24 hours of delivery and keep it well watered.