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Grass Seed Calculator

Calculate exact amount of grass seed needed for your lawn. Enter area dimensions and grass type to get seeding rates and bag quantities.

Calculate Grass Seed

Lawn Area

Calculation Results

๐ŸŒฑ Seed Required

Weight (lbs)
12.0
pounds
Weight (kg)
5.4
kilograms
Coverage Area
2000 sq ft
Seeding Rate
6 lbs/1000 sq ft
Estimated Cost
$48.00

๐Ÿ“ฆ Bags Needed

3
5 lb bags
2
10 lb bags
1
25 lb bags

Tall Fescue

Climate: Transition zone
Germination: 7-14 days
Application: New Lawn Establishment

๐Ÿ’ก Recommendations

  • ๐Ÿ’ก For new lawns, prepare soil by tilling, removing debris, and adding compost for best germination.
  • ๐Ÿ’ง Keep soil consistently moist (not soaked) for first 2-3 weeks until grass is 2 inches tall.

Related Calculators

Grass Type Comparison

Grass TypeNew Lawn RateOverseeding RateClimate ZoneGermination
Kentucky Bluegrass2 lbs/1000 sq ft1 lb/1000 sq ftCool (North)14-30 days
Perennial Ryegrass5 lbs/1000 sq ft3 lbs/1000 sq ftCool (North)5-10 days
Tall Fescue6 lbs/1000 sq ft4 lbs/1000 sq ftTransition7-14 days
Fine Fescue3 lbs/1000 sq ft2 lbs/1000 sq ftCool (Shade)7-14 days
Bermuda Grass1 lb/1000 sq ft0.5 lb/1000 sq ftWarm (South)7-21 days
Zoysia Grass1.5 lbs/1000 sq ft0.75 lb/1000 sq ftWarm (South)14-21 days

Note: Rates shown are for pure seed. Seed mixes may require different rates - always check product label.

Seeding Rate Guide

๐Ÿ“ How to Calculate Seed Amount

Step 1: Measure your lawn area (Length ร— Width = Square Feet)
Step 2: Divide by 1000 (e.g., 5000 sq ft รท 1000 = 5)
Step 3: Multiply by seeding rate for your grass type
Step 4: Add 10-20% extra for uneven spreading and bare spots

Example Calculation:
Lawn: 50 ft ร— 40 ft = 2000 sq ft
Grass: Tall Fescue (6 lbs/1000 sq ft for new lawn)
Calculation: (2000 รท 1000) ร— 6 = 12 lbs
With 15% extra: 12 ร— 1.15 = 13.8 lbs
Buy: 14-15 lbs of Tall Fescue seed
๐ŸŒฑ Light Seeding (Overseeding)

Use 50% of new lawn rate. For established lawns with thin spots. Less seed needed as existing grass fills gaps.

๐ŸŒฟ Heavy Seeding (New Lawn)

Use full recommended rate. For bare soil or complete renovation. More seed ensures thick, lush lawn.

โš–๏ธ Don't Overseed

Too much seed causes crowding, weak grass, and disease. Stick to recommended rates - more isn't better.

๐Ÿ“ฆ Bag Sizes

5 lb bags for small areas (<1000 sq ft). 10-25 lb bags for medium (1000-5000 sq ft). 50 lb bags for large areas.

Step-by-Step Seeding Process

1
Prepare Soil

Clear debris, till soil 4-6 inches deep, add compost, level surface. For overseeding: mow short and rake.

2
Test & Amend Soil

Test pH (ideal 6.0-7.0). Add lime if acidic, sulfur if alkaline. Mix in starter fertilizer.

3
Spread Seed

Use broadcast or drop spreader. Apply half in one direction, half perpendicular for even coverage.

4
Cover Seed

Lightly rake seed into top 1/4 inch of soil. Or spread thin layer of straw mulch (1 bale per 1000 sq ft).

5
Water Frequently

Keep soil moist (not soaked) for first 2-3 weeks. Water 2-3 times daily for 5-10 minutes until germination.

6
First Mowing

Wait until grass is 3-4 inches tall. Mow to 2-3 inches. Ensure mower blade is sharp to avoid pulling seedlings.

New Lawn vs Overseeding

๐ŸŒฟ New Lawn Establishment

When: Starting from bare soil, complete lawn renovation
Seeding Rate: 100% of recommended rate (e.g., 6 lbs/1000 sq ft for Tall Fescue)
Soil Prep: Full tilling, grading, amending required
Germination: 1-3 weeks depending on grass type
Usable: 6-8 weeks after seeding (when grass is 3" tall)
Cost: Higher due to soil prep and more seed
Best Time: Fall for cool-season, late spring for warm-season

๐ŸŒฑ Overseeding

When: Filling thin spots, improving existing lawn
Seeding Rate: 50% of new lawn rate (e.g., 3-4 lbs/1000 sq ft)
Soil Prep: Minimal - mow short, rake to expose soil
Germination: Same as new lawn, but competing with existing grass
Usable: 2-3 weeks (light use), existing grass provides coverage
Cost: Lower - less seed, minimal prep work
Best Time: Early fall for cool-season grasses

Tip: For severely damaged lawns (>50% bare), new lawn establishment is more effective than overseeding.

Common Mistakes to Avoid

โŒ
Seeding Wrong Time of Year

Planting in hot summer or late fall leads to poor germination and seedling death. Cool-season grasses: seed in early fall or spring. Warm-season: late spring. Timing is critical for success.

โŒ
Using Too Much or Too Little Seed

Too much seed causes crowding, weak grass, and disease susceptibility. Too little leaves bare spots and thin lawn. Follow recommended seeding rates exactly - use spreader settings for accuracy.

โŒ
Poor Soil Preparation

Seeding on compacted, poor soil wastes seed and money. Hard soil prevents root growth. Always till, amend with compost, and level soil before seeding. Good soil = healthy lawn.

โŒ
Inadequate Watering

Letting soil dry out during germination kills seedlings. Water 2-3 times daily (morning, midday, evening) for 5-10 minutes each. Keep soil consistently moist (not puddled) for first 2-3 weeks.

โŒ
Choosing Wrong Grass Type

Planting warm-season grass in northern climate (or vice versa) guarantees failure. Cool-season (Bluegrass, Fescue, Ryegrass): zones 2-7. Warm-season (Bermuda, Zoysia): zones 7-10. Match grass to your climate zone.

Frequently Asked Questions

How much grass seed do I need per square foot?
Seeding rates vary by grass type: Kentucky Bluegrass: 2 lbs/1000 sq ft (new lawn), 1 lb (overseeding). Perennial Ryegrass: 5 lbs/1000 sq ft (new), 3 lbs (overseeding). Tall Fescue: 6 lbs/1000 sq ft (new), 4 lbs (overseeding). Fine Fescue: 3 lbs/1000 sq ft. Bermuda: 1 lb/1000 sq ft. For 1000 sq ft lawn with Tall Fescue, need 6 lbs seed (new lawn) or 4 lbs (overseeding). Always buy 10-20% extra for bare spots and uneven spreading.
What is the best time to plant grass seed?
Cool-season grasses (Kentucky Bluegrass, Fescue, Ryegrass): Best in early fall (August-September) when soil is warm but air is cooling. Second best: early spring (March-April). Warm-season grasses (Bermuda, Zoysia, Centipede): Late spring to early summer (May-June) when soil temperature reaches 65-70ยฐF. Fall planting allows grass to establish before winter. Spring planting risks summer heat stress. Avoid seeding in summer (too hot) or late fall (frost kills seedlings).
How do I calculate grass seed for an irregularly shaped lawn?
For irregular shapes: Divide lawn into simple shapes (rectangles, circles, triangles). Measure each section separately. Calculate area for each: Rectangle: length ร— width. Circle: ฯ€ ร— radiusยฒ. Triangle: (base ร— height) / 2. Add all section areas together for total square footage. Example: L-shaped lawn = two rectangles. Rectangle A: 30 ft ร— 20 ft = 600 sq ft. Rectangle B: 20 ft ร— 15 ft = 300 sq ft. Total: 900 sq ft. Then multiply total by seeding rate for your grass type.
Should I use a seed blend or single grass variety?
Seed blends (recommended for most lawns): Mix of 2-3 compatible grass types provides disease resistance, adapts to varying sun/shade, more resilient to weather/traffic. Example: Tall Fescue + Perennial Ryegrass blend. Single variety: Use when specific trait needed (e.g., 100% shade tolerance with Fine Fescue, 100% Kentucky Bluegrass for premium appearance). Best practice: Choose blend suited to your climate zone. Cool-season areas: Fescue/Bluegrass/Ryegrass mix. Warm-season areas: Bermuda or Zoysia (usually single variety). Read seed tag for germination rate (>75% good, >85% excellent).
How much does grass seed cost?
Grass seed prices (per pound, 2024 average): Economy mix: $2-4/lb. Kentucky Bluegrass: $3-6/lb (premium varieties $8-12/lb). Perennial Ryegrass: $2-4/lb. Tall Fescue: $2-5/lb. Fine Fescue: $3-6/lb. Bermuda: $4-8/lb. Zoysia: $6-12/lb. Bag sizes affect price: 5 lb bag: $15-30. 10 lb bag: $25-50 (better value). 25 lb bag: $50-100 (best value for large areas). 50 lb bag: $80-150. For 1000 sq ft with Tall Fescue: 6 lbs ร— $3/lb = $18. For 5000 sq ft: 30 lbs needed, buy 10 lb bags or 25 lb bag for savings.
What is overseeding and when should I do it?
Overseeding is spreading grass seed over existing lawn to fill thin spots, improve density, and introduce improved grass varieties without full lawn renovation. When to overseed: Cool-season lawns: Early fall (August-September) is best, early spring second choice. Warm-season lawns: Late spring (May) when soil warms to 65ยฐF. Frequency: Annual overseeding recommended for high-traffic lawns, every 2-3 years for normal lawns. Process: Mow existing grass short (1.5-2 inches), rake or dethatch to expose soil, spread seed at half the rate of new lawn, water lightly daily for 2 weeks. Overseeding rate: 50% of new lawn rate (e.g., Tall Fescue: 4 lbs/1000 sq ft vs 6 lbs for new lawn).
How do I prepare soil for grass seed?
Soil preparation steps for best germination: 1. Remove debris: Clear rocks, old grass (if starting new), weeds. Use sod cutter for existing grass removal. 2. Test soil: pH should be 6.0-7.0 for most grasses. Add lime if too acidic (<6.0) or sulfur if too alkaline (>7.5). 3. Till soil: Loosen top 4-6 inches with rototiller. Breaks up compacted soil for root growth. 4. Add amendments: Mix in 2-3 inches of compost or topsoil. Improves drainage and nutrient retention. 5. Level and grade: Use rake to create smooth, level surface. Ensure proper drainage away from buildings. 6. Firm soil: Roll lightly or walk over to eliminate air pockets. 7. Final rake: Create fine, crumbly seedbed. Ready to seed. Skip tilling for overseeding - just rake to expose soil.