Mulch & Compost Calculator

Calculate exactly how much mulch or compost you need — no waste, no guesswork.

Bed Shape

Select a material to see the recommended depth.

Your Results

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Cubic Yards
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Cubic Feet
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2 cu ft Bags
standard size
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3 cu ft Bags
large size
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Weight (lbs)
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Weight (tons)
Estimated Cost
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Mulch Comparison Guide

All seven mulch types side by side — depths, best uses, pros and cons.

Mulch Type Rec. Depth Range Best Uses Pros Cons

How to Apply Mulch Correctly

  1. 1
    Clear weeds first. Pull or smother any existing weeds before laying mulch. Mulch suppresses new weeds but will not kill established ones underneath.
  2. 2
    Water the bed. Thoroughly moisten the soil before applying. Dry soil under mulch stays dry — mulch locks in whatever moisture is present when you lay it.
  3. 3
    Apply at the correct depth. Spread evenly to your chosen depth (2–4" for most bark mulches, 3–5" for pine straw, 2" for gravel). Too shallow and weeds break through; too deep and roots suffocate.
  4. 4
    Keep mulch 2–3 inches away from plant stems and tree trunks. "Volcano mulching" — piling mulch against bark — traps moisture, causes rot, and invites pests. Leave a ring of bare soil around every stem.
  5. 5
    Refresh annually. Organic mulches break down and thin out over one season. Rake existing mulch each spring to break up any matted layers, then top up to the original depth. This also incorporates the decomposed material into the soil.

Compost Comparison Guide

All six compost types — nutrients, application rates, best uses, and what to avoid.

Compost Type N-P-K (approx.) New Bed Rate Existing Bed Rate Best For Avoid For

Compost Application Rates by Situation

Situation Rate / Mix Method Notes
New raised bed (fill) 50–100% compost Fill bed entirely, or blend 50/50 with topsoil 100% compost works well for most vegetables; 50/50 is more economical for large beds
Amending existing bed 2–4 inches Spread on surface and fork or till into top 6–8" Do this each spring or fall; improves structure and feeds soil life
Top dressing established plants 0.5–1 inch Spread around drip line; do not touch stems Worms and rain pull nutrients down into the root zone naturally
Lawn overseeding ¼–½ inch Rake thinly over seeded area; keep moist Protects seeds from drying out and provides starter nutrients
Seed starting mix 30–40% compost Blend with perlite and coco coir or vermiculite Use finished compost only — fresh compost can burn seedlings and harbour pathogens

Compost Tea Ratio Calculator

Enter your water volume to find how much compost to use for an aerated compost tea (ACT) or a simple steep tea.

Aerated Tea (ACT)
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1:5 ratio · aerate 24–36 hrs
Steep Tea (simple)
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1:10 ratio · steep 24–48 hrs

ACT (1:5): Use an aquarium pump and airstone to aerate — this multiplies beneficial bacteria and fungi. Apply immediately after brewing, before microbes die off.
Steep tea (1:10): Place compost in a burlap or mesh bag and steep in water. Simpler, but less biologically active. Use within 4 hours of steeping.
Apply at the base of plants or as a foliar spray in the morning. Dilute further (1:1 with water) for sensitive seedlings.