Grass Seed Calculator

How much grass seed do I need? Multiply lawn length × width for square feet, then pounds = (area ÷ 1,000) × rate per 1,000 sq ft. New lawns often use about 6 lb per 1,000 sq ft; overseeding about 3 lb — but rates vary by species, so always check the bag label for your mix.

Reviewed / updated August 2026

Full walkthrough: How to Estimate Materials for Any Home Project

Your inputs

ft
ft

Presets are planning averages — always follow your seed bag label

Result

Seed to buy

6 lb

1,000 sq ft · ~6 lb / 1,000 sq ft

Lawn area
1,000 sq ft
Rate used
6 lb / 1,000 sq ft
Pounds of seed
6 lb

1,000 sq ft at ~6 lb per 1,000 sq ft (New lawn (general)) needs about 6 lb of seed (rounded up). Rates vary by species — check the bag.

Suggested next steps

  • Seed bag labels override these presets — use the rate printed for your exact mix and region.
  • For a new lawn, prep a smooth seedbed and keep soil evenly moist until germination.
  • A smaller bag or two is usually enough — avoid overseeding too heavily, which crowds seedlings.

How the grass seed calculation works

  1. Area (sq ft) = length × width
  2. Exact pounds = (area ÷ 1,000) × rate per 1,000 sq ft
  3. Buy = ceil(exact pounds)

Presets include new lawn (~6), overseed (~3), plus clearly labeled species examples (tall fescue, Kentucky bluegrass, Bermuda). These are planning averages for DIY estimates—not a substitute for the rate printed on your bag. Pure live seed percentage, filler, and regional mixes all change how heavy you should sow.

Source note: Seeding rates vary by cultivar, pure live seed percentage, and region. Always follow the rate printed on your seed bag or from your local cooperative extension. Updated August 2026.

Worked example

Lawn 50 × 20 ft (1,000 sq ft), new lawn rate 6 lb / 1,000 sq ft:

  1. Area = 50 × 20 = 1,000 sq ft
  2. Exact = (1,000 ÷ 1,000) × 6 = 6 lb
  3. Buy = 6 lb (already a whole pound)

Switch to Overseed (~3) for the same area and you need about 3 lb. Prep a smooth seedbed, ensure seed-to-soil contact, and keep moisture even until germination. Lightly rake and roll after spreading so seed is not left sitting on thatch. Also: Mulch Calculator, Gravel Calculator, BTU Calculator.

Tips and related tools

Frequently asked questions

How much seed for a new lawn vs overseeding?

As a planning average, new lawns often use about 6 lb per 1,000 sq ft and overseeding about 3 lb per 1,000 sq ft. Species differ — tall fescue mixes may need more, Bermuda less. This calculator’s presets are starting points; the seed bag is the authority.

Do Kentucky bluegrass and fescue use the same rate?

No. Kentucky bluegrass new-lawn rates are often around 2–3 lb per 1,000 sq ft, while tall fescue blends may be closer to 6–10 lb. Pick the labeled preset that matches your grass type, then confirm against the package.

Why round pounds up?

You buy whole packages. Rounding up avoids shorting thin edges and patchy spots. Do not dramatically over-seed — too much seed crowds seedlings and wastes money.

When should I seed?

Cool-season grasses are often seeded in early fall or spring; warm-season grasses prefer late spring into summer, depending on your USDA zone. Local extension guidance beats a generic calendar.

Can I mix new-lawn and overseed rates?

Use the rate that matches your job. Bare soil usually needs the higher new-lawn rate; thickening an existing lawn uses the lower overseed rate so you do not crowd seedlings.

Related tools

Related calculators — live tools and upcoming pages for internal linking.