Lawn Seed Calculator
Calculate how much grass seed is needed for a new lawn or overseeding, based on lawn area and seeding rate.
Adjust if your seed bag recommends a different rate
Result
Seed Needed
30.0 lbs
How to Use the Lawn Seed Calculator
Enter your lawn area in square feet and choose whether you're seeding a brand new lawn (bare soil) or overseeding an existing lawn to thicken it up. Each application type has a different recommended seeding rate per 1,000 square feet — new lawns need much more seed since there's no existing grass to fill in gaps. The default rate for your selection is editable if your seed bag recommends a different rate.
Example
A 5,000 sq ft new lawn at the default rate of 6 lbs per 1,000 sq ft needs (5,000 / 1000) × 6 = 30 lbs of seed. The same lawn, if just overseeding at 3 lbs per 1,000 sq ft, would need only 15 lbs.
Common Use Cases
- Buying the right amount of grass seed before starting a new lawn from scratch.
- Budgeting seed for an annual or seasonal overseeding to thicken thinning turf.
- Comparing seed cost between a full reseed and a lighter overseeding maintenance approach.
FAQs
- Why does a new lawn need so much more seed than overseeding? A new lawn starts from bare soil, so every seed needs to establish and fill in the space on its own. Overseeding fills gaps in an already-established lawn, so a lighter rate is enough to thicken the turf without wasting seed or causing overcrowding.
- Should I use the exact rate this tool defaults to? Treat the defaults as a reasonable general starting point — always check the seed bag's label for the specific grass species and blend you're using, since recommended rates vary by grass type, and adjust the rate field to match.
- Does this account for seed waste or uneven coverage? No — it calculates the straightforward amount based on area and rate. Many gardeners buy a small extra margin (5-10%) to account for uneven spreading, wind, or birds eating exposed seed.