Grass Seed Calculator

US & Canada

Pick your grass and enter the lawn size to get the seed to buy, at the rate a university extension or provincial government publishes.

Your lawn

1. Area to seed

ft
ft

2. Grass and job

lb / 1,000 sq ft
%

Leave your own rate at 0 to use the extension rate for the grass you picked, or copy the rate printed on your seed bag. Pure live seed = germination × purity; leave at 100% unless your rate is given as pure live seed.

Result

0

How much seed

More seed is not better: NC State warns heavy rates give weak, thin stands that are more prone to disease.

How the seed maths works

  • Seed = area ÷ 1,000 sq ft × rate in lb per 1,000 sq ft
  • With a pure live seed rate, divide by the PLS fraction on the label
  • Metric: 1 lb per 1,000 sq ft = 4.882 g/m² (calculated)

Most sources give a range. The calculator shows both ends; staying inside the range matters more than hitting the top of it. A rate printed on your seed bag is a better guide than any table, so enter it as your own rate if it differs.

Seeding rates by grass

Each row is one source. Metric is calculated except for the New Brunswick rows, which the source printed in metric.

Grass seeding rates by species and job, with source
Grass and job As printed g/m² Source
New lawn: Kentucky bluegrass 2-3 lb per 1,000 sq ft (100% KBG) 9.8 to 14.6 Penn State
New lawn: Perennial ryegrass 4-5 lb per 1,000 sq ft (100%) 19.5 to 24.4 Penn State
New lawn: Tall fescue (turf-type) 6-8 lb per 1,000 sq ft 29.3 to 39.1 Penn State
New lawn: Fine fescue Fine fescues 4-5 lb per 1,000 sq ft (100%) 19.5 to 24.4 Penn State
New lawn: Bermudagrass 1 to 2 pounds per 1,000 sq ft 4.9 to 9.8 NC State
New lawn: Zoysiagrass 1-2 lb per 1,000 sq ft 4.9 to 9.8 NC State
New lawn: Centipedegrass 0.25-0.50 lb per 1,000 sq ft 1.2 to 2.4 NC State
New lawn: Canadian sun mix (New Brunswick) approximately 1.5 kg per 100 m2 15 New Brunswick
New lawn: Canadian shade mix (New Brunswick) approximately 2.0 kg per 100 m2 20 New Brunswick
Overseeding: Kentucky bluegrass around 2 lbs. per 1000 ft2 9.8 Nebraska
Overseeding: Perennial ryegrass Perennial ryegrass 4-6 lb per 1,000 sq ft 19.5 to 29.3 Penn State
Overseeding: Tall fescue 3-4 lbs. per 1000 ft2 14.6 to 19.5 Nebraska
Overseeding: Ryegrass into bermudagrass (winter) 5-10 lbs per 1000 square feet for lawns 24.4 to 48.8 Virginia Coop. Ext.
St. Augustinegrass (plugs or sod only) No seed rate: sprigs, plugs or sod n/a NC State

Other published rates

Sources disagree a little. These are the other new-lawn rates we found, for comparison:

  • Kentucky bluegrass: NC State Table 9-4, 1.5 to 2 lb; Virginia, 1.5 to 2.5 lb; UC IPM, 2 to 3 lb.
  • Perennial ryegrass: Virginia, 3 to 5 lb; UC IPM, 6 to 9 lb.
  • Tall fescue: NC State, 6 lb; Virginia, 4 to 6 lb; UC IPM, 8 to 10 lb.
  • Fine fescue: Virginia, 3 to 5 lb; NC State, 1.5 lb when mixed with tall fescue or Kentucky bluegrass.
  • Bermudagrass: Virginia, 0.5 to 1 lb of pure live seed; UC IPM, 1 lb.
  • Zoysiagrass: Virginia, 2 to 3 lb of pure live seed.
  • Centipedegrass: Virginia, 1/4 to 1/2 lb of pure live seed.

All in lb per 1,000 sq ft. Enter any of them as your own rate.

Sources

For Canada, New Brunswick's metric rate is the only provincial figure we could verify; we have not found a published Ontario rate. Pound to kilogram and per-area conversions are calculated.

Common questions

How much grass seed do I need for 1,000 sq ft?
It depends on the grass. Kentucky bluegrass for a new lawn is 2 to 3 lb per 1,000 sq ft (Penn State); turf-type tall fescue is 6 to 8 lb. Pick your grass in the calculator for the rate and the source.
How much tall fescue seed for 5,000 sq ft?
For a new lawn at Penn State's 6 to 8 lb per 1,000 sq ft, 30 to 40 lb (13.6 to 18.1 kg). For overseeding at Nebraska's 3 to 4 lb, 15 to 20 lb.
How much grass seed per square metre in Canada?
The New Brunswick government recommends about 1.5 kg per 100 m² for a general mix (40 to 60% Kentucky bluegrass, 20 to 40% creeping red fescue, 10 to 20% perennial ryegrass), which is 15 g/m², and about 2.0 kg per 100 m² for a shade mix. So 100 m² takes 1.5 kg of the general mix.
How much seed for overseeding?
Less than for a new lawn for most grasses: Nebraska gives about 2 lb per 1,000 sq ft for Kentucky bluegrass and 3 to 4 lb for tall fescue. Perennial ryegrass is 4 to 6 lb (Penn State), so 2,000 sq ft takes 8 to 12 lb.
Can you grow St. Augustine from seed?
No. NC State's seeding table has no seed rate for St. Augustinegrass, and Virginia Cooperative Extension says it "can be established by plugs or by sod". Use the sod calculator instead.
What is pure live seed (PLS)?
The share of the bag that is viable seed of the variety you want: germination × purity. Virginia Cooperative Extension's example: a rate of 2 lb PLS per 1,000 sq ft with 83.3% PLS means 2 ÷ 0.833 = 2.4 lb of seed from the bag.
Is more grass seed better?
No. NC State Extension: "Higher seeding rates can result in weak, thin stands that are more susceptible to disease and high temperature stress."