Grass Seed Calculator
Calculate pounds of grass seed for a new lawn or an overseed, by grass type and area.
What you need
1.8lb
Product needed — Total weight to buy at the rate you selected.
- Area being treated
- 200 sq ft
- Bags needed
- 1
Estimates for planning. Confirm quantities with your supplier before ordering — see the assumptions below for the figures used.
Shop this project
The supplies a grass seed job usually takes. Quantities come straight from your calculation above — check them against your supplier's pack sizes before ordering.
Your shopping list
- Grass seed
- 1.8 lb
Materials
Grass seed
Starter fertilizer
High-phosphorus blend for new seed or fresh sod.
Topsoil
Prep & extras
Soil test kit
Worth doing before you fertilize — it tells you what is actually short.
Tools & equipment
Broadcast spreader
Garden rake
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How to use the grass seed calculator
Seeding rates vary by a factor of five between grass types — Kentucky bluegrass goes down at 2 to 3 pounds per 1,000 square feet, tall fescue at 8 to 10. Pick your seed type and this calculator handles the rest.
What this calculator assumes
Every estimate depends on figures that vary by supplier and conditions. These are the ones used here, so you can sanity-check the result against your own quote.
- Rates are expressed per 1,000 square feet, the standard used on North American product labels.
- Bag counts are rounded up. Buying one spare bag is usually worth it — running short mid-application leaves visible stripes.
- Rates are mid-range values for good quality seed. Cheap seed with a high inert or weed-seed fraction needs more; always read the label's pure live seed figure.
- Overseeding rates assume you are thickening an existing lawn, not repairing bare ground. Bare patches need the new-lawn rate.
Frequently asked questions
How much grass seed do I need per 1,000 square feet?
It depends entirely on the species. Tall fescue needs 8 to 10 pounds for a new lawn, perennial ryegrass 7 to 9, Kentucky bluegrass only 2 to 3, and centipede as little as half a pound. Overseeding an existing lawn takes roughly half the new-lawn rate.
Can I use too much grass seed?
Yes, and it is a common mistake. Overseeded ground produces crowded seedlings that compete for water and light, then thin out and become disease-prone. Doubling the rate does not give you a thicker lawn — it gives you a weaker one.
When is the best time to plant grass seed?
For cool-season grasses, late summer to early autumn is best — warm soil, cooler air and less weed competition. Spring is a distant second. Warm-season grasses go in late spring to early summer once soil temperatures are reliably above 65 °F.
How do I measure an irregular lawn?
Break it into rectangles, circles and triangles, calculate each and add them up. Subtract large features like a patio, driveway or pool — but do not bother subtracting flower beds smaller than a few square yards.
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