Grass Seed Calculator

Estimate how much grass seed you need for a new lawn, overseeding, or bare-area repair. Use a common grass type or enter the application rate printed on your seed bag.

Lawn Information

Project Type

Grass Type

Application Rate

lb per 1,000 sq ft

Preset rates are planning estimates. Use the application rate printed on your seed bag when available.

Lawn Area

Area Entry Method

Area Unit

Total Lawn Area

Seed and Purchase Details

Extra Seed Allowance (%)

Bag Size (lb)

Price per Bag ($)

The extra allowance covers overlap, spreading loss, and small measuring errors.

Adjust a pure-seed target using the seed tag

Use this only when the application rate represents a pure-seed target. Do not use it with a product’s printed application rate.

How the Calculator Works

Seed needed = lawn area ÷ 1,000 × application rate. The calculator then adds the selected extra-seed allowance.

If seed-tag adjustment is enabled, it also accounts for the percentage of pure seed expected to germinate.

Planning Notes

Measure only the areas that will receive seed.
Subtract buildings, pavement, gardens, and patios.
Break irregular lawns into smaller shapes and add their areas.
Use the product’s printed application rate whenever available.
Round bag quantities up so you do not run short.

Results are planning estimates. Grass varieties, seed blends, coatings, climate, soil preparation, and product instructions can change the amount required. Follow the seed product label and appropriate local guidance.