Lawn Seed Calculator

Calculate the amount of grass seed needed based on lawn size, grass type, and whether it is a new lawn or overseeding.

Results

Visualization

How It Works

Different grass species require different seeding rates. This calculator uses the standard rate per 1,000 square feet for your chosen grass type and halves it automatically if you are overseeding an existing lawn rather than starting fresh.

The Formula

Seed (lbs) = (Area_sqft / 1000) x Rate_per_1000

Variables

  • Area_sqft — Lawn area in square feet (Length x Width)
  • Rate_per_1000 — Lbs of seed per 1,000 sqft: Bluegrass 2, Bermuda 1, Fescue 6, Rye 8
  • Overseeding — If overseeding, the rate is halved (existing grass fills gaps)

Example

A 50 ft x 30 ft new lawn with Fescue: 1,500 sqft x 6 lbs/1000 sqft = 9 lbs of seed. At $4/lb, seed cost is $36. That is two 5 lb bags.

Tips

  • The best time to seed cool-season grasses (Bluegrass, Fescue, Rye) is early fall -- soil is warm, air is cool.
  • Bermuda and other warm-season grasses should be seeded in late spring after the last frost.
  • Keep newly seeded areas moist (but not flooded) until germination -- light watering 2-3 times daily.
  • Use a starter fertilizer at seeding time -- it is high in phosphorus to promote root growth.
  • Avoid mowing new grass until it reaches 3-4 inches tall, then mow to 2.5-3 inches.