Garden & Landscaping calculator
Grass Seed Calculator
Calculate grass-seed quantity from lawn area, the manufacturer's sowing rate and an extra allowance.
Calculate grass-seed quantity from lawn area, the manufacturer's sowing rate and an extra allowance. Keep the dimensions and units consistent, then check the figures that describe the product or layout you will really use. In this calculation, new-lawn versus overseeding rate can change the answer materially. Do not use one universal sowing rate. Seed mixtures specify different grams per square metre for new lawns and overseeding.
What you need to enter
The Grass Seed Calculator uses the following project information to calculate the result.
- Lawn area
- Application rate
- Extra allowance (%)
Calculator result
Seed / turf quantity
How the Grass Seed Calculator works
For grass seed quantity from lawn area and sowing rate, the calculator uses area × application rate × allowance. The mathematics is only one part of the estimate: getting new-lawn versus overseeding rate right usually matters more to the real-world result than extra decimal places. Unit conversion happens before the calculation.
Grass Seed Calculator worked example
Grass Seed Calculator example: For a 100 m² lawn using a seed or application rate of 35 g/m², the base requirement is 3.5 kg. A 10% allowance brings the planning quantity to 3.85 kg; use the actual rate printed for grass seed quantity from lawn area and sowing rate. Use the numerical result as the starting point, then verify new-lawn versus overseeding rate against the material, layout or equipment actually being used.
Important calculation assumptions
For grass seed quantity from lawn area and sowing rate, do not use one universal sowing rate. Seed mixtures specify different grams per square metre for new lawns and overseeding.
Frequently asked questions
Which real-world inputs does the Grass Seed Calculator rely on?
Measure lawn area and enter the seed maker's application rate for either a new lawn or overseeding. On this page, the measurements are used specifically for grass seed quantity from lawn area and sowing rate.
Why should I check new-lawn versus overseeding rate in the Grass Seed Calculator?
For the Grass Seed Calculator, use project-specific values for new-lawn versus overseeding rate. Do not use one universal sowing rate. Seed mixtures specify different grams per square metre for new lawns and overseeding.
What should I check before buying from the Grass Seed Calculator result?
For the Grass Seed Calculator, use the seed manufacturer's rate for the job type, then round to available pack sizes. New lawns and overseeding often require different rates. This keeps the estimate connected to the actual product, site or design.