Landscape & Groundwork

Grass Seed Calculator

Convert a new-lawn or overseeding label rate into seed weight and whole packages.

Units

Your measurements

Results update as you type.

Example shown — use your own measurements.

For 5 lb per 1,000 ft², enter 5 lb above and 1,000 ft² here. Use the selected application rate from your own label.

Extra options & cost (optional)

Applied once. Choose an allowance for your project; zero adds no extra material.

Fractions and number formats

Use decimals (12.5), fractions (12 1/2 or 12-1/2), or explicit lengths (12ft 6in, 12′ 6″, 25 mm). A comma followed by one or two digits is a decimal comma: 12,5 = 12.5. Grouped commas mean thousands: 1,200 = 1200. Use a decimal point for ambiguous values. Scientific notation is not accepted.

Enter your measurements

Results update as you type.

About this calculator

Convert a new-lawn or overseeding label rate into seed weight and whole packages. Enter your measurements and check the worked example below. Product quantities use the label information you supply.

How to measure

  • Measure the actual usable surface or internal space, using the field labels for the selected mode.
  • Keep openings and excluded areas separate so they are subtracted once.
  • Recheck units and label coverage before ordering.

How to use this calculator

  1. Enter the lawn area and choose the application label you are using.
  2. Copy both seed mass and area from the matching new-lawn or overseeding rate on your product label.
  3. Enter seed mass per package and any extra allowance once.
  4. Read required seed mass and whole packages; changing the application label does not replace the entered rate.

Formula

Seed mass = lawn area / label-rate area × label-rate mass × allowance factor

Packages = ceiling(seed mass / seed mass per package)

Assumptions

  • The chosen application label must match the mass-per-area rate copied from the actual product.
  • Switching new-lawn/overseeding records context only; it does not select a universal rate.
  • Extra mass is applied once before whole packages round up.

Common mistakes

  • Applying the same allowance in both measurements and the extra-material field.
  • Entering coverage or yield from a different product or measurement basis.
  • Treating a quantity estimate as an installation or structural approval.

Worked example

Try it: press “Load example” above the form.

At an illustrative label rate of 5 lb per 1,000 ft², a 1,000 ft² lawn needs 5 lb. With 3 lb packages, buy 2 packages before extra.

Limitations

No seeding rate is recommended. New-lawn and overseeding rates differ by species and product; switching the application label does not replace your entered rate. Climate, purity, preparation, germination and growing conditions are outside this estimate.

Frequently asked questions

Does selecting overseeding automatically change the seed rate?

No. The selector records the application context. Copy the matching new-lawn or overseeding mass-per-area rate from your actual label; the calculator does not supply or switch a universal rate.

What does the worked example show?

At an illustrative label rate of 5 lb per 1,000 ft², a 1,000 ft² lawn needs 5 lb. With 3 lb packages, buy 2 packages before extra.

How are seed weight and packages calculated?

Multiply lawn area divided by the label-rate area by the label-rate mass. Apply your extra allowance once, then divide by the actual seed mass per package and round up. The result does not predict germination.

What affects real seed performance beyond the package count?

No seeding rate is recommended. New-lawn and overseeding rates differ by species and product; switching the application label does not replace your entered rate. Climate, purity, preparation, germination and growing conditions are outside this estimate.

Reviewed by Codex AI editorial agent (Editorial, 2026-11-12).

Sources

Sources explain the methods and any named product presets. Check your product label where coverage, yield or density differs.

  • NIST: Revised Unit Conversion Factors
  • Defined geometric and purchase-quantity model

    Formulae on this page define the arithmetic model. Worked examples are illustrative, not product or installation recommendations.

Calculation documentation · Updated 2026-11-11 · Version 1.6.4. Estimates are planning aids. Confirm quantities, coverage and prices with your supplier before purchasing. Found an error? Report it.

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