Illinois Lawn, Seed, Sod & Landscape Calculator
Estimate grass seed, sod, fertilizer product, and bulk mulch, topsoil, or gravel quantities for an Illinois lawn or garden project — with general regional timing context, never a prescribed application rate.
Lawn & Landscape Calculator
Estimate seed, sod, fertilizer, and bulk material quantities for Illinois lawn and garden projects.
In central Illinois, late-summer to early-fall establishment is generally favored from late August through the first half of October. Always confirm current timing with University of Illinois Extension for your county before planting.
This tool estimates material quantities only — it does not calculate pesticide application rates and does not prescribe a fertilizer program. Soil test before applying fertilizer or amendments, always follow the product label's rates and instructions, keep fertilizer and soil amendments off pavement and out of storm drains, and check local watershed or runoff protection ordinances before applying.
Total area you plan to seed or overseed.
Use the seeding rate printed on your seed product's label — rates vary by species and blend.
This tool provides a planning estimate only. Always verify field measurements, product packaging and supplier yields, manufacturer instructions, and local code and permit requirements before purchasing materials or beginning work. This calculator does not collect or save any personal information — nothing you enter here is stored.
How this is calculated
Each tab uses a distinct, transparent formula based only on the numbers you enter:
- Seed:
seed (lb) = (area ÷ 1,000) × seed rate (lb per 1,000 sq ft), using the seeding rate printed on your product's label. - Sod:
adjusted area = area × (1 + waste %), then divided by your supplier's coverage per unit and rounded up to a whole unit. - Fertilizer:
product (lb) = (area ÷ 1,000) × target N rate ÷ (product's N % ÷ 100), where the target rate and N percentage both come from your soil test and product label. - Bulk material:
cubic feet = area × depth (in) ÷ 12, converted to cubic yards (÷ 27), increased by your waste allowance, and optionally divided by a bag size.
Worked example
For a 1,000 sq ft central Illinois lawn:
- Seed at 5 lb / 1,000 sq ft5 lb of seed
- Sod, 5% waste, 9 sq ft per slab1,050 adjusted sq ft ÷ 9 ≈ 117 slabs
- Fertilizer, target 1 lb N / 1,000 sq ft, product is 20% N1 ÷ 0.20 = 5 lb of product
- Mulch over 500 sq ft, 3 in deep, 10% waste125 cu ft → 4.63 cu yd → 5.09 cu yd with waste
Measuring tips
Measure lawn or bed area as length × width in feet, subtracting hardscape, beds, or structures that won't be seeded or mulched. For irregular shapes, break the space into rectangles and add the pieces together.
For bulk materials, measure planned depth with a tape measure at several points — mulch is typically applied 2–3 inches deep, topsoil for new beds 4–6 inches, and gravel paths 2–4 inches, but always follow your project's specific plan.