Grass Seed Calculator

How this calculator works

Seed labels may give different rates for establishing a new lawn, overseeding an existing lawn, or repairing bare patches. Enter the rate that matches your project and grass blend. Do not substitute a generic rate if the product label provides specific instructions.

seed pounds = lawn area ÷ 1,000 × label rate
bags = ceil(seed pounds ÷ bag size)

Worked example

For 5,000 sq ft at 6 lb per 1,000 sq ft: 5 × 6 = 30 lb of seed. With 25 lb bags, ceil(30 ÷ 25) = 2 bags.

Measure only the area you plan to seed

For a rectangular area, multiply length by width. Break irregular lawns into simple shapes and add their areas; exclude patios, beds, and other places that will not be seeded. If your measured area is in square yards, multiply by 9 to convert it to square feet.

Prepare and apply according to the label

Seed-to-soil contact, watering, season, and soil preparation affect results but do not change the area calculation. The calculator rounds up to whole bags and does not account for partial bags already on hand. Follow the seed label for spreading, coverage, and watering.

Frequently asked questions

How much grass seed do I need per 1,000 square feet?

It depends on the grass species, seed blend, and whether you are planting a new lawn or overseeding. Use the pounds-per-area rate printed on your seed package.

How do I calculate grass seed for my lawn?

Multiply the lawn area in square feet by the label rate in pounds per 1,000 square feet, then divide by 1,000. Divide the result by bag weight and round up to whole bags.

Should I use a different rate for overseeding?

Often yes. Product labels commonly specify separate rates for new lawns and overseeding. Select the rate appropriate to your task from the specific label.

Does this calculator include seed for bare patches?

Only if you include those patch areas in your total lawn area and enter the appropriate product rate. Small repairs may have different label recommendations.

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