How Much Mulch Do I Need? Free Calculator (2026)

Mulch is sold two ways — by the cubic yard (bulk) and by the 2 cubic foot bag — and the two prices are wildly different per square foot. Order wrong and you either pay double or come up three beds short on a Saturday afternoon. This guide gives you the exact mulch calculator formula landscapers use, a depth chart by mulch type, and 2026 pricing for bagged and bulk delivery.

The mulch calculator formula

Cubic yards of mulch = (Square feet × Depth in inches) ÷ 324

The 324 is the conversion factor: one cubic yard covers 324 sq ft at 1 inch deep, 162 sq ft at 2 inches, 108 sq ft at 3 inches, or 81 sq ft at 4 inches. Memorize 108 — most beds get 3 inches of mulch, so one yard covers ~108 sq ft.

How to calculate mulch step by step

Step 1 — Measure the bed area

For rectangular beds: Length × Width. For curved beds: pace it out roughly, or break it into rectangles and circles. A circle is π × radius² (π ≈ 3.14). Don't sweat exact numbers — mulch settles and you want to be slightly over.

Example: a 20 ft × 4 ft foundation bed = 80 sq ft. A 6 ft round tree ring = 3.14 × 3² = 28 sq ft.

Step 2 — Pick your depth

• New beds (no existing mulch) — 3 inches
• Refresh on existing mulch — 1 to 2 inches
• Around trees — 3 to 4 inches (keep 3" away from the trunk)
• Vegetable garden — 2 inches
• Playground or pathways — 4 to 6 inches
• Weed suppression in bare soil — 4 inches

Step 3 — Run the formula

Worked example: 200 sq ft of foundation beds at 3" deep = (200 × 3) ÷ 324 = 1.85 cubic yards. Round up to 2 yards bulk, or buy 25 bags (each 2 cu ft bag covers ~8 sq ft at 3").

Mulch coverage chart (1 cubic yard)

• 1 inch deep — 324 sq ft
• 2 inches deep — 162 sq ft
• 3 inches deep — 108 sq ft (most common)
• 4 inches deep — 81 sq ft
• 6 inches deep — 54 sq ft (playgrounds)

Bags vs bulk: which costs less?

One cubic yard equals 13.5 bags of 2 cu ft mulch. Bulk wins on price almost every time over 2 yards:

• Bagged mulch (2 cu ft) — $3 to $6 per bag = $40 to $80 per cubic yard equivalent
• Bulk mulch (delivered) — $30 to $50 per cubic yard for standard hardwood, $40 to $80 for dyed or premium
• Bulk delivery fee — $50 to $100 flat (often free over 3–5 yards)
• Break-even: bulk usually wins above 2 cubic yards (~27 bags)

Mulch cost per yard (2026)

• Shredded hardwood — $30 to $45 per cu yd
• Dyed mulch (black, brown, red) — $35 to $55 per cu yd
• Pine bark / pine straw — $40 to $60 per cu yd
• Cedar — $45 to $70 per cu yd
• Cypress — $40 to $60 per cu yd
• Rubber mulch (playground) — $130 to $200 per cu yd
• Installed (mulch + labor spreading) — $60 to $120 per cu yd

For the 200 sq ft example at 3" deep (2 yards): bulk hardwood ~$70 + $75 delivery = $145. Same job in bags: 25 bags × $4 = $100, plus your truck and a sore back.

How much mulch do I need for common projects?

• Small foundation bed (20 × 4 ft) at 3" — 0.75 cu yd / 10 bags
• Average front yard beds (200 sq ft total) at 3" — 2 cu yd / 25 bags
• Large landscape (500 sq ft of beds) at 3" — 4.6 cu yd / 63 bags
• Single tree ring (6 ft diameter) at 4" — 0.35 cu yd / 5 bags
• Vegetable garden (10 × 20 ft) at 2" — 1.25 cu yd / 17 bags
• Playground (20 × 20 ft) at 6" — 7.5 cu yd / 100 bags

Mulch types: which one should I buy?

• Shredded hardwood — best all-purpose, breaks down in 1 year, feeds soil
• Dyed black or brown — best curb appeal, holds color 1–2 years
• Pine bark nuggets — best for slopes (won't wash away), lasts 2+ years
• Cedar — best for repelling insects, naturally rot-resistant
• Cypress — best for moisture retention in hot climates
• Rubber — best for playgrounds, lasts 10+ years (don't use in garden beds)
• Pine straw — best in the Southeast US, easy to spread, lasts 6 months

When and how often to mulch

Mulch once a year in early spring (March–May) after the soil warms but before weeds germinate. A light 1" refresh is enough on existing beds — total depth should stay at 3 to 4 inches. Piling mulch over 4 inches against tree trunks causes rot (the dreaded 'mulch volcano').

Frequently asked mulch questions

How many bags of mulch in a cubic yard?

13.5 bags of 2 cubic foot mulch, or 9 bags of 3 cubic foot mulch. Most home improvement stores sell the 2 cu ft size — so divide cubic yards by 13.5 to skip the math and just remember 1 yard ≈ 14 bags.

How thick should mulch be?

3 inches is the sweet spot for most beds — enough to suppress weeds and retain moisture, not so much that water can't reach the roots. Drop to 2" for veggies and seedlings, bump to 4" for weed-heavy or unmulched soil.

How much does a yard of mulch cover?

At 3 inches deep, one cubic yard covers 108 square feet — about a 10 × 11 ft area. At 2 inches it covers 162 sq ft, at 4 inches it covers 81 sq ft.

Should I remove old mulch before adding new?

No — if existing mulch is under 3" deep, just top-dress. Remove old mulch only if it's matted, moldy, or has built up past 4". Fluff the surface with a rake before adding new to break up any crust.

How much does mulch cost installed?

In 2026, landscapers charge $60 to $120 per cubic yard installed (mulch + labor to spread it). A typical $200 home with 2 yards of mulch costs $120 to $240 done-for-you, or $90–$150 DIY with bulk delivery.

Use the free mulch calculator

Skip the math — punch your bed dimensions and depth into the calculators on our home page and get cubic yards, bags, and total cost in one click. The exact landscaper formula above is built in, including the depth-to-coverage conversion so you order the right amount the first time.