About this calculator
How much grass seed to buy for a new lawn or overseeding, using typical sowing rates for each seed type.
How it’s calculated
Seed (kg) = area × rate (g/m²) ÷ 1,000. Rates used for a new lawn: couch about 10 g/m², kikuyu about 5 g/m², tall fescue about 35 g/m² and ryegrass about 40 g/m². The rate on the seed pack takes priority.
Worked example
With these inputs:
- Area shape
- Rectangle
- Length
- 10 m
- Width
- 8 m
- Job
- New lawn
- Seed type
- Couch
the result is:
- Seed needed
- 0.8 kg
Tips from the trade
- Split the seed in half and sow in two directions for even cover.
- Keep the seedbed moist (not soaked) until the grass is established.
Results are estimates for planning and pricing. Check quantities against your drawings, the manufacturer’s data and the NCC and Australian Standards before ordering.