Grass Seed & Sod Calculator
Pick whether you're seeding or laying sod, then enter your lawn's length and width. For seed, choose the grass type and whether it's a new lawn or an overseed — the calculator returns the pounds of seed using the species' seeding rate. For sod, choose how it's sold (pallet, roll or slab) and it returns the pieces to buy, including a trim allowance.
Your measurements
Seed is cheaper with more grass choices but takes weeks to fill in; sod is an instant lawn at a higher price. This switches the answer between pounds of seed and pieces of sod.
The longer side of the area you're planting.
The shorter side. For an irregular yard, split it into rectangles and add them up.
Seed size differs hugely by species, so the pounds-per-1,000-ft² rate does too — tiny bluegrass seed needs far less weight than coarse fescue or ryegrass.
A new lawn seeds bare soil at the full rate. Overseeding thickens an existing lawn at half the rate — the established grass shades out anything more, so doubling up just wastes seed.
Grass seed to buy
7 lb
covers 1,000 ft² · 7 lb per 1,000 ft² (new lawn)
What to buy
- Tall fescue seed
- 7 lb
- Starter fertilizer
- 1 bag(~5,000 ft² per bag)
Seed is sold by the pound and in bags rated for a coverage area — match the bag's “new lawn” or “overseed” rating to your square footage.
A high-phosphorus “starter” fertilizer put down with the seed feeds germinating roots.
Seed needed for 1,000 ft² by grass type
Estimates only. Verify against your supplier's coverage figures before ordering.
Footprint
Footprint to scale
The numbers
- Lawn area
- 1,000 ft²(40 × 25 ft)
- Seeding rate
- 7 lb / 1,000 ft²(new lawn (full rate))
- Coverage area
- 111 yd²(same lawn, in square yards)
Tall fescue is a cool-season grass. Overseeding an existing lawn would use half this rate.
The formula
Seed (lb) = Area ÷ 1,000 × rate (lb per 1,000 ft²) · overseed = ½ new-lawn rate | Sod pieces = ⌈Area × (1 + waste %) ÷ coverage per piece⌉
Example: A 40 × 25 ft lawn is 1,000 ft². In tall fescue (7 lb per 1,000 ft²) a new lawn needs 7 lb of seed; overseeding halves that to ~3.5 lb. As sod with 5% waste it's 1,050 ft² — 3 pallets (450 ft² each) or 105 rolls.
How it works
- 1Measure the lawn and multiply length × width for the area in square feet (add up rectangles for an irregular yard).
- 2For seed: every grass species has a seeding rate in pounds per 1,000 ft². Multiply your area (in thousands of ft²) by that rate.
- 3Seeding a new lawn uses the full rate; overseeding an existing lawn uses half — more just gets shaded out.
- 4For sod: add a small waste allowance for trimming, then divide by the coverage of your format — ~450 ft² a pallet, 10 ft² a roll, 2.67 ft² a slab — and round up.
- 5Put down a starter (high-phosphorus) fertilizer either way to feed the new roots.
Frequently asked questions
How much grass seed do I need per 1,000 square feet?
It depends on the species, because seed size varies enormously. Typical new-lawn rates per 1,000 ft² are 6–8 lb for tall fescue and perennial ryegrass, 2–3 lb for Kentucky bluegrass, 4–5 lb for fine fescue, 1–2 lb for Bermuda or Zoysia, and about 0.5–1 lb for centipede. Overseeding an existing lawn uses half those amounts.
How much grass seed for a new lawn vs overseeding?
Overseeding uses half the new-lawn rate. A new lawn covers bare soil and needs the full rate; overseeding only thickens existing turf, and the established grass shades out any extra seedlings, so doubling up wastes seed without improving the lawn.
How much sod do I need?
Multiply the lawn's length by its width for the area in square feet, then add 5% for trimming (10–15% if it has lots of curves or obstacles). Divide by the coverage of your sod format: a pallet covers about 450 ft², a 2×5 ft roll covers 10 ft², and a 16×24 in slab covers about 2.67 ft². Round up to whole pieces.
How many square feet does a pallet of sod cover?
Most sod pallets cover about 450–500 square feet, though it varies by region and grower — some are as low as 400. This calculator defaults to 450 ft² per pallet; check your supplier and adjust the coverage under Advanced options. A pallet weighs roughly 2,000 lb.
Is it cheaper to seed or sod a lawn?
Seed is far cheaper up front — a few cents per square foot versus roughly $0.35–$0.85 per square foot for sod material, before labor. Sod's advantage is an instant, weed-free lawn you can install almost any time in the growing season, while seed needs the right season and several weeks of watering to fill in.