Grass Seed Calculator

Estimate seed for new lawns or overseeding, build blends, draw your lawn on a map, plan bag counts & cost, and export a shareable plan.

1) Lawn Area

Tip: You can enter one shape, add multiple sections, or draw on the map.
ft
ft
Area = Length × Width. Switch units above to use meters/yards.
Shape Dimension A Dimension B Area (auto)
Shapes: Rectangle (L×W), Circle (Diameter), Triangle (Base×Height), or Custom (enter area).
Draw a polygon around your lawn. Edit or delete as needed. OpenStreetMap tiles are used; no API key required.

Total Area

0 ft²
0 yd²
0 m² · 0 acres
Tip: For irregular lawns, either add multiple sections or draw on the map.
Precision: Switch to meters for metric measurements.

Measuring Basics (Quick Diagrams)

Length Width
Measure the longest length and widest width. Multiply to estimate area for rectangular spaces.
Break into sections or draw with the map tool.
For curves/odd shapes, split into simple sections (rectangles/triangles) or use the map drawing option.

2) Seeding Options

Grass typePercent
Tip: Percentages should sum to 100%. The calculator auto-averages recommended seeding rates.
Tilled soil often needs slightly less seed; existing lawns pair with overseeding.
Cool-season grasses suit zones ~3–7; warm-season grasses suit zones ~7–11.
lbs / 1000 ft²
Auto-filled by type/mode/conditions; editable.
lbs
$
lbs
$

3) Results

Total seed needed

0.00 lbs
0.00 kg

Seed bags

0 bags
Cost: $0.00

Fertilizer plan

0 bags
Cost: $0.00

Grand total

$0.00
Rate: 0.0 lbs / 1000 ft²

Recommended seeding density (reference)


Germination & coverage timeline

  • Select a grass type/blend and calculate to see estimated dates based on today.

FAQs

It depends on grass type and whether it’s a new lawn or overseeding. For example, Kentucky bluegrass is often ~2.5 lbs/1,000 ft² new and ~1.5 lbs/1,000 ft² overseeding, while tall fescue is higher at ~7.0 and ~3.5 respectively. Use the calculator to auto‑fill recommended rates and adjust for shade/traffic.

New lawns need higher rates to establish from bare soil. Overseeding fills gaps in an existing stand, so recommended rates are lower. Soil prep and conditions (shade/traffic) also influence the final rate.

Either break it into simple shapes in the Multi‑section tab (rectangles, triangles, circles) or use the Map tab to draw a polygon around your yard. The tool sums all sections and converts units automatically.

Cool-season grasses (bluegrass, ryegrass, fescues) prefer spring/fall windows in cooler zones (3–7). Warm-season types (Bermuda, Zoysia, Centipede) establish best in late spring/early summer in warmer zones (7–11). Always check local guidance.

Many lawn pros recommend about 1.0 lb of Nitrogen per 1,000 ft² at seeding. The fertilizer add‑on here converts your product’s N% and bag weight into bags needed and optional cost.

Depends on type and conditions. Ryegrass can sprout in 5–10 days, fescues in 7–14, bluegrass in 14–30, Bermuda 7–14, Zoysia 14–21. The timeline panel shows estimated dates.

Related Calculators

Fertilizer CalculatorPlant Population CalculatorPlant Spacing Calculatorhow much potting mix do i need calculatorhow much soil calculatorZoysia Overseeding CalculatorKentucky Bluegrass Seed Calculatorraised garden bed soil calculator

Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.