The Lawn Grass Seed & Overseeding Calculator determines the exact weight of seed and number of 20-pound bags required for new lawn establishment or fall overseeding.

### Seed Rates by Turfgrass Species Seeding density depends on seed size and growth habit. Fine seeds like Kentucky Bluegrass contain millions of seeds per pound and require far less weight than larger coarse seeds like Tall Fescue: - **Tall Fescue**: $8\text{ lbs per } 1{,}000\text{ sq ft}$ for new bare lawns; $4\text{ lbs per } 1{,}000\text{ sq ft}$ for overseeding. - **Kentucky Bluegrass**: $3\text{ lbs per } 1{,}000\text{ sq ft}$ for new lawns; $1.5\text{ lbs per } 1{,}000\text{ sq ft}$ for overseeding. - **Bermuda Grass**: $2\text{ lbs per } 1{,}000\text{ sq ft}$ for new lawns; $1\text{ lb per } 1{,}000\text{ sq ft}$ for overseeding. - **Overseeding Adjustment**: Existing turf already provides partial ground cover, so overseeding applies exactly half ($50\%$) of the full bare-soil seeding rate.

### Worked Lawn Sizing Example Suppose you plan to overseed a **$6{,}500\text{ sq ft}$** front and back yard with **Tall Fescue**: - **Application Rate**: $4\text{ lbs per } 1{,}000\text{ sq ft}$ (overseeding rate) - **Total Seed Weight**: $$\text{Seed Needed} = \left(\frac{6{,}500}{1{,}000}\right) \times 4 = 6.5 \times 4 = 26\text{ lbs}$$ - **Bag Calculation**: $\lceil 26 / 20 \rceil = 2$ twenty-pound bags (with $14\text{ lbs}$ remaining for bare spot touchups).

### In-Browser Yard Calculations All yard area dimensions and bag requirements calculate locally in your client browser. No property dimensions, landscaping plans, or addresses are stored or transmitted.