Grass Seed Calculator
Enter the lawn's length and width, choose a seed and the published rate range that goes with it, or type the rate from your seed bag, and get the pounds of seed and the bags to buy, rounded up once, counted at the high end of the range so the count never falls short.
Estimates for planning, not professional advice. Read the full notice.
The drawing did not open. Length and width are still here.
Lawn: shape and size
Skip the drawingDrag a round corner to move it. The small hollow diamond on a side is its curve handle: drag it across the side to curve the side (it is not a corner). To add a corner (a new point), tap the side itself, then choose Add a point here. Tapping a corner or a side opens its actions. Drag empty space to move the view; pinch, or Ctrl and the mouse wheel, to zoom. The keys are listed under Keys.
Keys
- Tab
- next corner; each says how far it is from corner 1
- Arrow keys on a corner
- move it one square; ten with Shift; 1/16 in with Alt
- Delete or Backspace
- remove the corner; its two sides join in one straight side
- + on a corner
- add a corner halfway along the next side
- Arrow keys on the drawing
- move the view; farther with Shift
- + and - on the drawing
- zoom in and out
- 0 on the drawing
- show the whole shape
- Ctrl+Z (Cmd+Z on a Mac)
- undo, except inside a typed field (it keeps its own)
- Ctrl+Shift+Z or Ctrl+Y
- redo
- Escape while dragging
- put it back where it was
- Enter on a corner or side
- go to its actions
- Escape in the actions
- close them and go back to the drawing
The drawing did not load. Check your connection and try again.
- Area
- 5,000 ft²
- Perimeter
- 300 ft
- Cut-out edges
No area until the shape is fixed.
Estimate for planning, from what you entered and the product data shown. Check product labels and your supplier before you buy.
Shape: Rectangle Change
Sides
Corners
Cut-outs
Feet and inches, like 12' 6"
Example: a rectangular lawn
1 50 lb bag
- Seed at the high end, in pounds 40 lb
- Seed at the low end, in pounds 30 lb
- Bags at the high end 1 × 50 lb bag
- Bags at the low end 1 × 50 lb bag
- Bags of the smaller size, at the high end 2 × 25 lb bags
Your project
Enter a size to see your total.
Each product is rounded up once for the whole project, so the total can be less than the items bought alone added together. A line counted from a cut layout (sheets, boards or tiles laid out piece by piece) is counted for each item and added.
Pounds and the range ends
These numbers follow the sizes above for every item in the list. The count above uses the high end of a published range, so it never falls short; the low end is shown beside it.
Shopping list
| Item | Size | Buy |
|---|---|---|
| Grass seed, by the bag | 50 lb bag | 1 |
Save on this device
Saved projects
No saved projects yet.
Worked example: a rectangular lawn
Show the working
- Area of the lawn 50 ft × 100 ft = 5,000 ft²
- Thousands of square feet: the area over a thousand square feet 5,000 ft² ÷ 1,000 ft² = 5 thousands of sq ft
- Pounds at the high end: thousands of square feet times the rate 5 thousands of sq ft × 8 lb per 1,000 sq ft[1] = 40 lb
- Bags: pounds over the bag size, rounded up once 40 lb ÷ 50 lb = 1 × 50 lb bag
Assumptions
The figures behind the example. Sourced figures link to their source below; a default is a starting value to check against your label or supplier.
| Assumption | Value | Details and changes |
|---|---|---|
| Tall fescue seed rate, Penn State Extension, low end | 6 lb per 1,000 sq ft[1] | |
| Penn State Extension: seeding rates in pounds per 1000 square feet are 2 to 3 for Kentucky bluegrass, 6 to 8 for turf-type tall fescue, 4 to 5 for turf-type perennial ryegrass and 4 to 5 for fine fescues. | ||
| Tall fescue seed rate, Penn State Extension, high end | 8 lb per 1,000 sq ft[1] | |
| Penn State Extension: seeding rates in pounds per 1000 square feet are 2 to 3 for Kentucky bluegrass, 6 to 8 for turf-type tall fescue, 4 to 5 for turf-type perennial ryegrass and 4 to 5 for fine fescues. | ||
| Tall fescue seed rate for a new lawn, Nebraska Extension, low end | 8 lb per 1,000 sq ft[2] | |
| University of Nebraska-Lincoln Extension: the full seeding rate is 3 to 4 pounds per 1,000 square feet for Kentucky bluegrass and 8 to 10 for tall fescue; overseeding is 1 to 2 for bluegrass and 4 to 6 for tall fescue. | ||
| Tall fescue seed rate for a new lawn, Nebraska Extension, high end | 10 lb per 1,000 sq ft[2] | |
| University of Nebraska-Lincoln Extension: the full seeding rate is 3 to 4 pounds per 1,000 square feet for Kentucky bluegrass and 8 to 10 for tall fescue; overseeding is 1 to 2 for bluegrass and 4 to 6 for tall fescue. | ||
| Seed bag size | 50 lb | |
| Default Check your label or supplier. | ||
Feet and inches, like 12' 6"
Seed in pounds at the high end of each range
Pounds of seed for four lawn sizes at the high end of each published range
| Seed and source | 1,000 sq ft | 5,000 sq ft | 10,000 sq ft | One acre |
|---|---|---|---|---|
| Kentucky bluegrass, Penn State Extension | 3 lb | 15 lb | 30 lb | 130.7 lb |
| Turf-type tall fescue, Penn State Extension | 8 lb | 40 lb | 80 lb | 348.5 lb |
| Turf-type perennial ryegrass, Penn State Extension | 5 lb | 25 lb | 50 lb | 217.8 lb |
| Fine fescues, Penn State Extension | 5 lb | 25 lb | 50 lb | 217.8 lb |
| Kentucky bluegrass, new lawn, Nebraska Extension | 4 lb | 20 lb | 40 lb | 174.2 lb |
| Tall fescue, new lawn, Nebraska Extension | 10 lb | 50 lb | 100 lb | 435.6 lb |
| Kentucky bluegrass, overseeding, Nebraska Extension | 2 lb | 10 lb | 20 lb | 87.1 lb |
| Tall fescue, overseeding, Nebraska Extension | 6 lb | 30 lb | 60 lb | 261.4 lb |
Each cell is the area over a thousand square feet times the rate, with no rounding. The two sources print different ranges, so both are listed.
Seed in pounds at the low end of each range
Pounds of seed for four lawn sizes at the low end of each published range
| Seed and source | 1,000 sq ft | 5,000 sq ft | 10,000 sq ft | One acre |
|---|---|---|---|---|
| Kentucky bluegrass, Penn State Extension | 2 lb | 10 lb | 20 lb | 87.1 lb |
| Turf-type tall fescue, Penn State Extension | 6 lb | 30 lb | 60 lb | 261.4 lb |
| Turf-type perennial ryegrass, Penn State Extension | 4 lb | 20 lb | 40 lb | 174.2 lb |
| Fine fescues, Penn State Extension | 4 lb | 20 lb | 40 lb | 174.2 lb |
| Kentucky bluegrass, new lawn, Nebraska Extension | 3 lb | 15 lb | 30 lb | 130.7 lb |
| Tall fescue, new lawn, Nebraska Extension | 8 lb | 40 lb | 80 lb | 348.5 lb |
| Kentucky bluegrass, overseeding, Nebraska Extension | 1 lb | 5 lb | 10 lb | 43.6 lb |
| Tall fescue, overseeding, Nebraska Extension | 4 lb | 20 lb | 40 lb | 174.2 lb |
The same sizes as above at the low end of each range.
Whole bags at the high end of each range
Whole bags of the starting bag size for four lawn sizes at the high end of each range
| Seed and source | 1,000 sq ft | 5,000 sq ft | 10,000 sq ft | One acre |
|---|---|---|---|---|
| Kentucky bluegrass, Penn State Extension | 1 × 50 lb bag | 1 × 50 lb bag | 1 × 50 lb bag | 3 × 50 lb bags |
| Turf-type tall fescue, Penn State Extension | 1 × 50 lb bag | 1 × 50 lb bag | 2 × 50 lb bags | 7 × 50 lb bags |
| Turf-type perennial ryegrass, Penn State Extension | 1 × 50 lb bag | 1 × 50 lb bag | 1 × 50 lb bag | 5 × 50 lb bags |
| Fine fescues, Penn State Extension | 1 × 50 lb bag | 1 × 50 lb bag | 1 × 50 lb bag | 5 × 50 lb bags |
| Kentucky bluegrass, new lawn, Nebraska Extension | 1 × 50 lb bag | 1 × 50 lb bag | 1 × 50 lb bag | 4 × 50 lb bags |
| Tall fescue, new lawn, Nebraska Extension | 1 × 50 lb bag | 1 × 50 lb bag | 2 × 50 lb bags | 9 × 50 lb bags |
| Kentucky bluegrass, overseeding, Nebraska Extension | 1 × 50 lb bag | 1 × 50 lb bag | 1 × 50 lb bag | 2 × 50 lb bags |
| Tall fescue, overseeding, Nebraska Extension | 1 × 50 lb bag | 1 × 50 lb bag | 2 × 50 lb bags | 6 × 50 lb bags |
Each cell rounds the pounds up once to whole bags of the starting bag size.
Questions
How much grass seed do I need per 1,000 square feet?
It depends on the seed. Penn State Extension and Nebraska Extension each print a range in pounds per thousand square feet for each kind, and the first table above lists them by lawn size. Pick the kind and the calculator multiplies the range by your area.
How much grass seed do I need per acre?
The last column of each table is one acre. It is the rate times the number of thousand-square-foot units in an acre, with no rounding in the pounds tables and one round-up to whole bags in the bags table.
How much seed does overseeding take?
Overseeding on an existing lawn uses less than a new lawn. Nebraska Extension prints separate, lower ranges for it, which are in the seed choices above.
Why does the count use the high end of the range?
A source prints a range, and counting with the low end can leave you short. The calculator counts with the high end and shows the low end beside it, so you can see both.
Sources (2)
-
Turfgrass Seed and Seed Mixtures (opens in new tab), Penn State Extension, web article.
Code or government.
“All seeding rates in this publication are in pounds per 1000 square feet.”
“Kentucky bluegrass 100% at 2-3 lb per 1,000 sq ft”
“Turf-type tall fescue 100% at 6-8 lb per 1,000 sq ft”
“Turf-type perennial ryegrass 100% at 4-5 lb per 1,000 sq ft”
“Fine fescues 100% at 4-5 lb per 1,000 sq ft”
Checked November 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 1) -
Spring Lawn Overseeding (opens in new tab), University of Nebraska-Lincoln Extension in Lancaster County, web article.
Code or government.
“The full seeding rate for Kentucky bluegrass is 3-4 lbs. per 1,000 sq.ft., and tall fescue 8-10 lbs. per 1,000 sq.ft.”
“bluegrass should be applied at 1-2 lbs. per 1,000 sq.ft. and tall fescue at 4-6 lbs. per 1,000 sq.ft.”
Checked November 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 2)
These are summaries of what the sources say, not professional advice. Codes and product data change. Check with your building department and the product label about your own project.
Sources
- [1] Penn State Extension, Turfgrass Seed and Seed Mixtures. Checked November 12, 2026. https://extension.psu.edu/turfgrass-seed-and-seed-mixtures
- [2] University of Nebraska-Lincoln Extension in Lancaster County, Spring Lawn Overseeding. Checked November 12, 2026. https://lancaster.unl.edu/spring-lawn-overseeding