Lawn Seed Calculator

Estimate seed for a new lawn or overseeding project using measured area, application rate, waste, bag size, and local material and labor costs.

22-calculator project library Reviewed 2026-07-25Calculations run privately in your browser

Enter project details

Example values are prefilled

Lawn and application

Lawn length

Average lawn width

Job type

Seed rate

lb per 1,000 sq ft

Use the seed label; lower this for overseeding as appropriate.

Overlap and waste allowance

Bag and cost

Bag weight

Price per bag

Preparation and seeding labor per 1,000 sq ft

Location and tax assumptions

The location factor adjusts labor only. Replace all default prices with actual local quotes before purchasing.

Local labor-cost factor

A coarse planning adjustment—not a ZIP-code quote.

Sales tax on materials

Enter the tax rate that applies to taxable materials.

All default prices are editable examples. Cost scenarios vary the entered plan; they do not represent bids or guarantees.

Calculate grass seed pounds, bags, coverage, starter fertilizer allowance, labor, and project cost.

Seed pounds = lawn area ÷ 1,000 × labeled application rate × (1 + extra %). Bags = seed pounds ÷ bag weight, rounded up.

Example: A 100 × 50 ft lawn is 5,000 sq ft. At 8 lb per 1,000 sq ft plus 8% extra, plan for 43.2 lb, or three 20 lb bags.

Seed rates vary by species, blend, germination rate, soil preparation, slope, and new-lawn versus overseeding use. Follow the product label.

Is overseeding rate lower than new-lawn rate?

Usually. Change the application rate to the product's overseeding instruction.

Should I measure landscaped islands?

Subtract non-lawn areas or divide the yard into simple rectangles and total only turf areas.

Does the calculator include soil or straw?

The shopping plan suggests them, but their quantities depend on site condition and are not priced here.