New lawn or overseeding?
Choose the application you plan to make. New lawns and overseeding existing turf often have different package coverage rates. Enter both coverage figures from your actual product label; the defaults are illustrative examples and do not recommend a rate for a particular seed.
Read the seed package
Use the labeled coverage for one bag and the net weight of that same bag. Coated seed or mixes containing fertilizer and mulch can have different weights and rates. Do not assume that two bags of the same weight cover the same lawn area.
Formula and example
Adjusted area = length × width × allowance factor. Bags = ceiling(adjusted area ÷ selected bag coverage). Estimated product weight to apply = adjusted area ÷ selected bag coverage × bag weight. A 1,000-square-foot lawn with no extra allowance and a 5-pound bag covering 1,000 square feet needs 1 bag. At an overseeding coverage of 3,000 square feet, the calculated application amount is 1.67 pounds, though you still need to purchase 1 whole bag.
Use allowance carefully
Extra allowance is an ordering allowance, not advice to exceed labeled application rates. Cost uses whole purchased bags plus your fixed charge. Soil preparation, fertilizer and watering costs are excluded.
Reference: Scotts grass seed FAQ. Follow the coverage and application instructions on your product.