Grass Size Calculator
Enter the lawn area, the type of grass seed and whether you are sowing a new lawn or overseeding. The calculator gives the seed needed, the sowing rate and how many bags to buy.
- Grass seed
- Sowing rate
- Bags
Overseeding thickens an existing lawn. A new lawn starts on bare soil.
Seed rates depend on the grass type and the job. Tall fescue sown on a new lawn needs about 8 lb per 1,000 sq ft. A 5,000 sq ft lawn needs about 40 lb, eight 5 lb bags. Overseeding uses about half as much.
Grass seed chart
Per 1,000 sq ft. Search for a seed.
| Seed | New lawn (lb) | Overseeding (lb) | New lawn (g/m²) |
|---|---|---|---|
| Tall fescue | 8 | 4 | 39 |
| Perennial ryegrass | 8 | 4 | 39 |
| Kentucky bluegrass | 3 | 1.5 | 15 |
| Fine fescue | 5 | 2.5 | 24 |
| Bermuda, hulled | 2 | 1 | 10 |
| General purpose mix | 7.2 | 4.1 | 35 |
Pounds.
Lawn area and seed
Tall fescue, new lawn. Slide the lawn area.
The bags of seed stack up beside the lawn.
How to sow grass seed
Area to bags. Step through it.
Area
Measure.
Sow in early autumn or spring when the soil is warm and moist.
Cool or warm season grass
Grass types. Compare them.
Cool season.
Cool season.
Warm season.
Cool season grasses suit cooler climates. Warm season grasses love heat.
Before you sow
Lawn checks. Tick each item.
Tick each item as you go.
Keep off the new lawn until it has been mown two or three times.
What you get
Seed sizing. Each tile explains one result.
Pounds.
Per area.
To buy.
New or over.
Daily.
Too much seed makes seedlings compete and can thin the lawn.
Frequently Asked Questions
No question matches that search.
How much grass seed do I need?
Multiply the area in thousands of square feet by the seed rate for your grass type.
How much grass seed per square metre?
About thirty-five grams for a general mix on a new lawn.
How much seed to overseed?
About half the new lawn rate.
How much seed for five thousand square feet?
About forty pounds of tall fescue for a new lawn.
When should I sow grass seed?
Early autumn or spring, when soil is warm and moist.
How often should I water new seed?
Lightly every day until it sprouts.
Can I sow too much seed?
Yes. Overcrowded seedlings compete and grow weak.
A thick, even lawn
Sow the right amount for the area and the seed, and the lawn comes up full with no bare patches.
More size calculators
Each one has its own calculator, worked examples and answers to common questions.