How this calculator works
A new lawn is just an area to cover, so the maths starts with the area of each section. Lawns are rarely all square corners, so each section can be a rectangle, a circle (round), an oval (curved) or a triangle, and the area is worked out to suit:
area (rectangle) = length × width
area (circle) = π × (diameter ÷ 2)²
area (oval) = (π ÷ 4) × length × width
area (curve) = (arc° ÷ 360) × π × (diameter ÷ 2)²
area (triangle) = ½ × base × height
section area = shape area − its cut-outs (garden beds, patios), never below zero
to cover = (sum of section areas) × wastage
Sod: pieces = ceil( to cover ÷ coverage of one piece )
pallets = ceil( pieces ÷ pieces per pallet )
Seed: weight = to cover × sowing rate
bags = ceil( weight ÷ bag weight )
Pick a shape for each section and a small diagram shows which dimension is which - the diameter of a round lawn, the two axes of an oval, the diameter and sweep angle of a curve, the base and height of a triangle. A curve is a sector you set by its arc angle, the same way the retaining-wall calculator does: 90° for a quarter, 180° for a half-round, 360° for a full circle. Each section can also have cut-outs - a garden bed, patio, pond or path the lawn wraps around - entered the way doors and windows are deducted on the drywall calculator. A cut-out is taken off its own section’s area (each clamped so it never goes below zero), then the sections pool into one order. Pick Sod to lay pre-grown turf and the calculator divides your net area by the coverage of one slab or roll, rounding up to whole pieces and whole pallets; or pick Seed and it multiplies by the sowing rate for the weight of seed and the bags. Add a section for each part of the lawn - a front, a round bed, a curved border - with a cut-out for anything to leave out, and they pool into one order. All the maths runs in exact metric internally, so switching between feet and metres never changes the answer.
Worked example
This example follows the unit system you pick in the calculator above.
A 10 m × 5 m back lawn laid with 1 m² turf rolls, 5% wastage:
- Area: 10 × 5 = 50 m².
- Add 5% for cuts at the edges: 50 × 1.05 = 52.5 m² to cover.
- At 1 m² per roll: ceil(52.5) = 53 rolls.
- At about 50 rolls a pallet, that is just over one pallet, so order 2 pallets.
Sod pieces and seed rates
The piece size sets how many you buy; the sowing rate sets how much seed you weigh out. These are the common figures:
| Item | Typical coverage / rate | Notes |
|---|
| Slab of sod (16 × 24 in) | ≈ 0.25 m² (≈ 2.7 sq ft) | Per slab; common for warm-season grasses |
| Pallet of slabs | ≈ 42–46 m² (≈ 450–500 sq ft) | ≈165 slabs; confirm with your supplier |
| Turf roll | 1 m² (≈ 10.8 sq ft) | Per roll (≈1640 × 610 mm) |
| Pallet of rolls | ≈ 50 m² (≈ 540 sq ft) | ≈50 rolls; confirm with your supplier |
| New lawn from seed | 35 g/m² (5–7 lb / 1,000 sq ft) | Full establishment rate |
| Overseeding | 25 g/m² (3–4 lb / 1,000 sq ft) | Thickening an existing lawn |
Pallet quantities and exact roll sizes differ between turf farms, so treat the pallet count as a guide and confirm the piece size before you order.
Sod or seed?
Both start a lawn over the same ground, and the calculator switches between them:
- Sod (turf) gives an instant, even lawn you can see straight away and use within a few weeks. It costs more per square foot, must be laid soon after delivery, and comes in fewer grass varieties.
- Seed is much cheaper, comes in more varieties, and suits large or awkward areas, but it takes weeks to establish and needs careful watering and protection while it germinates.
Many people sod the visible front lawn for an instant finish and seed a larger back lawn to save money - enter each area and switch the mode to compare the quantity each needs. For the full trade-off, see sod vs seed, and for the seed side, how much grass seed do I need.
Sod by grass type
The calculator counts pieces the same way whatever the grass - you choose the piece size, not the variety. What changes by type is the price and how it is established:
- St. Augustine - broad-bladed and the most shade-tolerant warm-season grass, laid as sod or plugs only (there is no St. Augustine seed). See St. Augustine grass.
- Zoysia - dense, fine and hard-wearing but slow to establish; most premium types are sod or plugs, a few (like Zenith) come from seed. See Zoysia grass.
- Bermuda and fescue - the more affordable, widely seeded options.
- Sir Walter buffalo (Australia) - the popular soft-leaf buffalo turf, sold as certified turf by the square metre. See Sir Walter buffalo grass.
Tips for measuring and ordering
- Split a curved or L-shaped lawn into rectangles, add one section per rectangle, and the calculator totals the area for you.
- Prepare and level the ground first, topping up with topsoil where it is low, so the sod or seed bed is ready before delivery.
- Lay sod as soon as it arrives - ideally within 24 hours - because it is living grass that dries out quickly on the pallet.
- Order a little generous rather than short; a second delivery of sod can be a slightly different cut or colour, and a part-used pallet still has to be paid for.
- Water new sod or seed daily until it roots or germinates, then taper off as it establishes.
For the full method and a worked example, see how much sod do I need, and to budget the job, how much does sod cost.
Buying turf where you are
In Canada, pre-grown grass is usually called sod and supplied as cut slabs about 16 × 24 in (roughly 2.7 sq ft each) stacked on pallets that cover around 450-500 sq ft, so you buy whole pieces and round up to whole pallets.
Pick the piece size you are actually buying in the calculator above so the count matches
what is on the truck.
For ground preparation, laying and the first weeks of care, see Turfgrass Producers International's Guideline Specifications to Turfgrass Sodding.