Grass Seed Calculator
Calculate how much grass seed you need for a new lawn or overseeding project.
Need the lawn area first?
Measure it on the satellite map and bring the square footage back here.
How the estimate is calculated
Grass seed is usually planned by pounds per 1,000 square feet. Use the bag label rate when it differs from the calculator default.
Base seed = (lawn area ÷ 1,000) × seed rate
Buffer seed = base seed × buffer %
Total seed = base seed + buffer seed
New lawn vs. overseeding
New lawns usually need more seed because the soil is bare. Overseeding uses less because existing grass already covers part of the lawn. Choose the purpose in the calculator above; rates change automatically.
Grass seed FAQ
How do I calculate how much grass seed I need?
Measure the lawn area in square feet, divide by 1,000, then multiply by the seed rate on the bag. This calculator also turns your buffer percentage into extra seed and adds it to the total.
How much grass seed do I need per 1,000 square feet?
It depends on the grass type and whether you are seeding bare soil or overseeding. New lawns usually need a higher rate than overseeding.
Do I need more seed for a new lawn or overseeding?
A new lawn usually needs more seed because there is no existing grass. Overseeding uses less because you are adding seed into existing turf.
Can I use this calculator if I only know length and width?
Yes. Choose the length × width estimate option, enter up to three simple lawn sections, and the calculator will estimate square footage first.
Should I buy extra grass seed?
A 10% buffer is a useful starting point for uneven spreading, thin spots, and small mistakes. Check your seed label before purchasing.
How do I choose the right grass seed type?
Start with the seed bag label when you have it. If the bag lists a different rate than the calculator default, choose Custom rate and enter the label amount. Otherwise pick the closest grass type for a planning estimate.
Need the lawn area first?
Search the address, trace the lawn, and use the square footage for seed planning.