Start with the product label
The tool has no default seed rate. Enter pounds per 1,000 ft² from the product you plan to use; do not treat another grass type’s rate as interchangeable.
Measured lawn area + the rate on your seed label
Grass Seed Calculator
How much grass seed do I need? Lawn area ÷ 1,000 × your seed-label rate gives pounds to apply. Enter your measured zones below, then add package weight to see whole bags and leftovers. New-lawn and overseeding rates stay yours.
The rate remains yours
How the grass seed calculator works
Measure each rectangle or enter its known area, then use the rate from the product you will apply. Each lawn zone keeps its own rate, so new-lawn and overseeding amounts can be calculated separately before their pounds are combined. The purchase result uses one package weight for that combined total: use one seed product per worksheet, and run different products separately. Whole bags and the leftover show the difference between applying seed and buying it.
Keep lawn zones separate
Give each measured area its own name, use and rate. This is useful when a renovation and an overseeding section have different product instructions.
See the purchase remainder
When package weight is known, the calculator rounds up to whole bags and reports how much remains after the planned amount.
A unit conversion, not a seed recommendation
Grass seed calculator for one acre
One acre is 43,560 ft². If a seed label gives a rate of R pounds per 1,000 ft², one acre requires 43.56 × R pounds before any planning allowance. The calculator uses your entered rate and can also accept an area directly in acres.
Worked unit example, not a seeding recommendation: If your chosen product label said 5 lb per 1,000 ft², a measured 2,000 ft² would calculate to 10 lb; one acre would calculate to 217.8 lb (43.56 × 5). Use your actual label rate, then enter package weight to see whole bags and the remainder.
From pounds to a shopping list: For that 2,000 ft² example, a user-chosen 10% allowance makes 11 lb planned. With 7 lb packages, buy 2 bags (14 lb) and expect 3 lb left. If your quoted price were $18 per bag and $5 delivery, the entered package cost would be $41. These are illustrative inputs, not a market price or recommended allowance.
There is no default seed rate or price. The result does not check germination, choose a grass species, or find a local supplier quote.
Common questions
Grass seed calculator FAQ
How much grass seed do I need?
Measure each lawn area, enter the matching product's rate in pounds per 1,000 ft², and add the calculated amounts. Enter package weight to see how many whole bags cover the planned total.
Can I use this as a lawn seed calculator?
Yes. Add each lawn zone and enter the label rate for its new-lawn or overseeding use. The selection never inserts a generic rate. Use one seed product per worksheet when calculating whole bags and cost.
How many pounds of grass seed per square foot?
Use the rate on your seed package. If it is stated per 1,000 ft², divide that label rate by 1,000 to express it per square foot. The calculator applies the full measured area.
How much grass seed do I need for one acre?
One acre is 43,560 ft², so multiply a label rate in lb per 1,000 ft² by 43.56 before any allowance. Or select acres for a known-area input.
Does this work as an overseeding calculator?
Yes. Choose Overseeding / repair for the zone and enter the rate for the seed product and use. Do not substitute a new-lawn rate unless the product instructions say to do so.
Why is there no preset seeding rate?
Rates depend on the grass species or mix, product and local conditions. Use the seed label or applicable local extension guidance; this page does not prescribe a universal rate.
Can I spread the seed in two passes?
The result panel can show half of your planned amount as an even arithmetic split. It is not a recommendation to use two passes; follow the label and spreader instructions for your product.
Does the estimate include seed price?
Enter package weight and package price to calculate cost; the delivery fee is optional. The calculator does not look up local prices or labor costs.
How much will a 50 lb bag of grass seed cover?
Before any allowance, coverage in ft² equals 50 ÷ your label rate in lb per 1,000 ft² × 1,000. At an illustrative rate of 5 lb per 1,000 ft², that is 10,000 ft². Use your actual product and application rate, not the example.
Continue the lawn project
Compare seed planning with other lawn materials
For ready-grown lawn coverage, use the sod calculator. For soil preparation, use the soil calculator; for drainage or a stone border, open the gravel calculator. Planning fertilizer quantities from a product label? Use the fertilizer calculator. Pricing the service work? Use the landscaping cost calculator for area-based or visit-based quotes.