Grass Seed Calculator
Work out how much grass seed you need for a new lawn — in kg or lb, and how many bags to buy.
Seeding rates differ between grass species and mixes — always check the rate printed on the seed bag. Sowing much more than recommended does not give a better lawn; the seedlings compete for light and water.
About this tool
Enter the lawn area, the seeding rate from the seed bag (g/m² or lb per 1,000 ft²) and the bag size. You get the amount of seed, the number of bags, how much one bag covers and the rate converted between metric and US units.
Frequently asked questions
Nordic lawn mixes are usually sown at about 10–20 g/m², i.e. 1–2 kg per 100 m² (Plantasjen; LOG’s Helt Grønn Standard says 1–1.5 kg per 100 m²). At 15 g/m², a 100 m² lawn needs 1.5 kg of seed.
Purdue Extension recommends about 2 lb per 1,000 ft² for Kentucky bluegrass, 3–4 lb for bluegrass with 10–15% perennial ryegrass and 5–9 lb for turf-type tall fescue, which has much larger seeds.
1 lb per 1,000 ft² equals 453.6 g spread over 92.9 m², which is 4.88 g/m². So 15 g/m² is about 3.1 lb per 1,000 ft², and 2 lb per 1,000 ft² is about 9.8 g/m².
In cool climates late summer (August–September) is ideal, when the soil is warm but the weather is cooler and moister; early spring also works. Plantasjen advises a temperature above 10 °C, and keep the seedbed moist until the grass is established.
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