Compost & Amendment Calculator | LandscapeCalculating.com

Compost & Amendment CalculatorCalculate compost, manure and soil amendment volume in cubic yards and bags for top-dressing lawns, amending beds and filling raised beds.Free compost & amendment calculator with formulas, waste factors, cost estimates and professional guidance.Formula: cubic yards = (area × depth ÷ 12) ÷ 27 × (1 + settling %); bags = volume ÷ bag sizeHow to use this calculator

Set the amendment depth by purpose: 1/4–1/2 in for a lawn top-dress, 2–3 in to amend beds, 6–12 in for raised beds.

Pick your bag size or order bulk by the cubic yard — the calculator shows both costs.

Carry 10% settling allowance so the finished grade holds after irrigation.

Frequently asked questions

How do I calculate how much compost I need?

Multiply area by depth in feet, divide by 27 for cubic yards, and add 10% for settling. This tool returns yards, bags and both cost options.

How much compost do I need to top-dress a lawn?

Spread 1/4–1/2 in of compost across the turf area. A 1,000 sq ft lawn at 1/4 in needs about 0.8 cubic yards, or roughly 11 1.5 cu ft bags.

How much compost to amend a garden bed?

Till 2–3 in of compost into the top 6–8 in of soil. A 100 sq ft bed at 3 in needs about 1.1 cubic yards.

How much does compost cost?

Bulk compost runs $35–$55 per cubic yard delivered; bagged compost runs $5–$8 per 1.5 cu ft bag. Bulk wins above about 8 bags.

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