Grass Seed Calculator
Stop guessing how much seed to buy. Enter your lawn dimensions, pick your product, and get the exact amount you need — with cost estimates and direct buy links.
Pro Tips for Seeding Success
Always buy 10% extra
Between spreader waste, uneven distribution, slopes, and edges, you will always use more seed than the math suggests. Running short mid-project is far worse than having a few extra pounds.
Use starter fertilizer
New grass seedlings need phosphorus for root development. Apply a starter fertilizer (like Scotts Turf Builder Starter) at the same time you seed. It makes a real difference in germination rates.
Seed-to-soil contact matters
The #1 reason seeds fail to germinate is poor soil contact. After spreading seed, lightly rake it into the top 1/4" of soil or use a lawn roller. Don't just throw seed on top of existing grass.
Water frequently, not heavily
Keep the seedbed consistently moist with light watering 2-3 times daily for the first 2-3 weeks. Heavy watering washes seeds away. Once seedlings are 2" tall, transition to deeper, less frequent watering.
How to Calculate Grass Seed Coverage
The amount of grass seed you need depends on three things: your lawn size, the type of grass, and whether you're starting a new lawn or overseeding an existing one. Different grass species have very different seeding rates — Kentucky Bluegrass seeds are tiny and need only 2-3 lbs per 1,000 sq ft, while tall fescue seeds are larger and need 6-8 lbs per 1,000 sq ft.
| Grass Type | New Lawn lbs / 1,000 sq ft | Overseeding lbs / 1,000 sq ft |
|---|---|---|
| Kentucky Bluegrass | 2-3 | 1-2 |
| Tall Fescue | 6-8 | 3-4 |
| Perennial Ryegrass | 8-10 | 3-5 |
| Fine Fescue | 4-5 | 3 |
| Bermudagrass | 2-3 | 1-2 |
| Zoysia | 2-3 | 1-2 |
| Centipede | 0.25-0.5 | 0.125-0.25 |
| Bahiagrass | 8-10 | 5 |
The Simple Formula
Seed needed (lbs) = (Lawn area in sq ft / 1,000) x Seeding rate per 1,000 sq ft
For example, if you have a 5,000 sq ft lawn and you're planting tall fescue (seeding rate: 7 lbs per 1,000 sq ft), you'd need: 5,000 / 1,000 x 7 = 35 lbs of seed.
Our calculator does this math automatically for every product in our catalog, accounts for waste with a configurable buffer, and tells you exactly how many bags to buy. It also calculates starter fertilizer needs if you're establishing a new lawn.