Grass Seed Calculator: How Much Seed Do I Need?
This grass seed calculator estimates pounds and bags of grass seed for a new lawn or overseeding from the lawn area and the grass type.
How to use
- Enter the lawn area in square feet.
- Choose the grass type, then new lawn or overseeding. Overseeding uses half the new-lawn rate.
- Leave the custom rate blank to use the typical rate, or type the pounds per 1,000 sq ft from the bag.
- Enter the bag size in pounds and read the pounds of seed and the bags to buy.
Formula
Pounds needed = lawn area / 1,000 × seeding rate. Overseeding uses half the new-lawn rate. Bags are the pounds divided by the bag size, rounded up to a whole bag. A custom rate replaces the typical rate for that grass.
Example. A 5,000 sq ft tall fescue lawn at 7 lb per 1,000 sq ft is 5,000 / 1,000 × 7 = 35 lb. A 5 lb bag means 7 bags. Overseeding that lawn at half the rate is 17.5 lb, which is 4 bags.
The bag label wins
The rates here are typical new-lawn amounts inside common ranges, not a soil test and not the rate for every blend or coated seed. If the bag prints a different number, enter that custom rate. Compare an instant lawn with the sod calculator.
Frequently asked questions
How much grass seed per 1,000 square feet?
It depends on the species. Tall fescue is often seeded around 6–8 lb per 1,000 sq ft for a new lawn, while Kentucky bluegrass needs only about 2–3 lb.
How much seed for overseeding?
Overseeding usually uses about half the new-lawn rate.
What is the formula?
Pounds needed = lawn area / 1,000 × seeding rate. A 5,000 sq ft tall fescue lawn at 7 lb is 35 lb.
Should I trust the bag label or the calculator?
The bag label. Blends and coated seed vary, so the tool lets you enter a custom rate.
Is seed or sod better?
Seed is cheaper; sod gives an instant lawn. Use the sod calculator to compare.
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