Grass Seed Rates: From Area to Bag Weight
Sowing rates look small in grams per square metre, but they add up across a lawn. This post shows the multiplication and the spreading allowance.
What is the Seed Coverage Calculator?
Enter the lawn area and the sowing rate in grams per square metre, and the tool multiplies them, adds a 10 percent allowance for uneven spreading, and gives the weight in kilograms. The allowance is shown separately.
How to use it
- Measure the lawn area in square metres.
- Enter the sowing rate from the seed packaging.
- Click Calculate Seed.
Worked example
100 sq m at 25 g per square metre needs 2.5 kg exactly, or 2.75 kg with the 10 percent allowance.
Does overseeding use a lower rate?
Yes, overseeding an existing lawn usually uses a lower rate than sowing bare soil.
Frequently asked questions
Can I sow by hand evenly?
A spreader gives a more even result than hand scattering, especially on larger lawns.
What if I sow too thickly?
Overcrowded seedlings compete and weaken, so stick close to the packaging rate.