How Much Area Does a Cubic Yard Cover? Coverage Chart by Depth

Want the quick version? Our cubic yard coverage calculator does this same math interactively — depth, area, and bags in one screen. This guide is the planner's reference: the rule, the full chart, and per-material project tables you can read before you order.

The one rule: 324 ÷ depth

One cubic yard is 27 cubic feet, and a cubic foot is 12 inches of depth over one square foot. Multiply: 27 ft³ × 12 in/ft = 324 square-foot-inches per cubic yard. So the area a yard covers at any depth is simply:

Square feet covered = 324 ÷ depth in inches

Depth of 2 inches? 324 ÷ 2 = 162 sq ft. Depth of 4 inches? 324 ÷ 4 = 81 sq ft. And at 12 inches the math self-checks: 324 ÷ 12 = 27 sq ft, because a yard is 27 cubic feet and a foot of depth over 27 sq ft is exactly 27 ft³. If your number ever contradicts that anchor, you did the arithmetic wrong — check it against the 12-inch column.

Going the other direction, the volume you need is the mirror image: cubic yards = (square feet × depth in inches) ÷ 324. A 300 sq ft area at 4 in needs 300 × 4 ÷ 324 = 3.70 yards. Add ~10% overage and order 4 yards. That is the whole engine behind every table below.

Master coverage table

Bookmark this. Every row is 324 divided by the depth, rounded to the nearest square foot:

One important caveat before the material tables: this chart gives placed, finished coverage. Bulk materials settle and compact — crushed stone can lose 10–15% of delivered volume to compaction, mulch settles ~10%, and topsoil settles under its own weight over weeks. Size your order with overage (10% is the site default), not the finished coverage. The distinction between delivered volume and finished depth is where most DIY shortages come from.

Mulch: the yard covers 162 sq ft at 2 in, 108 at 3 in

Mulch is the most common “how many yards do I need?” question, and the answer sits in the first two rows of the chart. Fresh bark or hardwood mulch at 2–3 inches is the standard bed depth — deeper smothers plant crowns and shallower doesn't suppress weeds. Bark mulch weighs about 800 lbs per cubic yard in our density library, so these yards are light and easy to spread.

Bag math: a 2 ft³ bag covers 2 ÷ (depth/12) sq ft — so 12 sq ft per bag at 2 in and 8 sq ft per bag at 3 in. The crossover point is around 10–12 bags: beyond that, bulk mulch delivered by the yard is usually cheaper per cubic foot and arrives with far less plastic to deal with. Run the exact numbers in our mulch calculator, which also prices bags vs bulk.

Gravel: 81 sq ft per yard at 4 in

Four inches of compacted gravel is the standard residential driveway and parking-pad depth, and at 4 in a cubic yard covers 81 sq ft — the number to remember. Gravel is heavy (crushed stone ≈ 2,800 lbs/yd³, i.e. 1.4 tons per yard), so the tonnage of your order matters for delivery trucks and dump-spot planning.

Remember the compaction caveat: these are compacted volumes. A vibratory roller squeezes roughly 10–15% of air out of fresh stone, so ordering exactly the finished yardage leaves the surface thin. Our gravel calculator adds compaction and waste automatically — use it rather than hand-dividing by 81. For full driveway planning (base layers, cost per ton), see our gravel driveway guide.

Topsoil: 54 sq ft per yard at 6 in

Six inches is the working depth for new lawns and garden grading — enough for grass roots and shallow perennials to establish. At 6 in, a cubic yard covers 54 sq ft. Screened topsoil runs about 2,400 lbs/yd³ (1.2 tons) in our density library.

Two cautions specific to topsoil. First, it settles — fresh topsoil can drop 10–20% over the first few weeks as it consolidates, so grade slightly high and let it settle before laying sod (our topsoil-for-sod guide covers the timing). Second, do not confuse topsoil with compost or garden soil when sizing a bed — see topsoil vs compost vs garden soil before you order. For raised-bed math specifically, there is a dedicated guide below.

Concrete: 81 sq ft per yard at 4 in

Concrete shares the 4-inch row with gravel, but the numbers that matter here are bags and ready-mix: a yard of concrete weighs 4,050 lbs, so it is never a DIY-with-bags decision at slab scale unless the scale is small. At 4 in a yard covers 81 sq ft.

The bag economics flip fast: at ~$5 per 80-lb bag, the 10×10 pad costs about $310 in bags vs roughly $200 for ready-mix delivery — but suppliers charge short-load fees under ~4–5 yards, so the bag route stays sensible up to about 1–1.5 yards. Our concrete calculator and bags-per-yard guide run the full comparison.

Bags-per-area notes

Suppliers sell mulch, gravel, and soil by the cubic foot in bags too. The conversion is the same engine: bags = ceil(total ft³ ÷ bag ft³), where total ft³ = sq ft × depth in feet.

• Mulch, 2 ft³ bags: 13.5 bags per yard (27 ÷ 2). 3 ft³ bags: 9 per yard.
• Concrete, 80-lb bags (0.60 ft³ yield): 45 per yard (27 ÷ 0.60). 60-lb bags (0.45 ft³): 60 per yard. 40-lb bags (0.30 ft³): 90 per yard.
• Bagged topsoil, 0.75 ft³ bags: 36 bags per yard — the breakpoint for bulk is usually around 30–40 bags.
• Always round up — a partially filled bag is not a product, and a one-bag shortage is a second trip.

If you are already thinking in bags, start from area instead: bags = (sq ft × depth in) ÷ (324 × bag ft³ ÷ ... ) — or just divide the sq-ft coverage number in the master table by the per-bag coverage. Example: mulch bed 200 sq ft at 3 in needs 200 ÷ 108 = 1.85 yards; in 2 ft³ bags that is 1.85 × 13.5 = 25 bags (matches the table above).

Loose, heaped, and compacted: what a “yard” really means

Not every “yard” is the same yard. Suppliers measure bulk material three different ways, and the differences explain most coverage surprises:

• Loose yard (struck level). The honest yard: a full bucket leveled flat, 27 ft³. Reputable bulk yards sell this way. Your coverage math above assumes this.
• Heaped yard. The bucket heaped above the rim — up to 10–15% more material. Some suppliers heap generously, which is a bonus, not a baseline; do not count on it.
• Compacted/placed yard. What the material becomes after rolling, watering, or settling — 10–15% less volume than the loose yard for stone, up to 20% for topsoil. This is why the order table above adds 10% before you buy.

When a supplier's price looks 15% cheaper than everyone else's, the usual explanation is a short bucket, not a better deal. Ask whether the yard is struck level. For bagged material the equivalent question is the yield: an 80-lb concrete bag yields 0.60 ft³, so 45 bags make a true yard — and a store-brand bag that yields 0.55 ft³ needs 50. The label always wins over the rule of thumb.

Common mistakes

Dividing by the wrong constant. 324 assumes depth in inches. If your depth is in feet, the constant is 27 — mixing them up by a factor of 12 is the most expensive arithmetic error in landscaping. Forgetting compaction and settle. Finished coverage is not delivered volume; add the 10% the calculators default to. Measuring depth from the wrong surface. Four inches of mulch over existing soil is not the same as four inches of new material — measure from the subgrade you are filling to, not from the grass. Treating “about a yard” as 1.0. 0.93 yards is not 1.0 when it is mulch at $45/yard — fine — but it is also not 1.0 when it is concrete in bags, where it is 42 bags. Round the final unit, not the yards. Ignoring the irregular-shape penalty. Real beds are not rectangles; measure the true square footage (our irregular-area guide shows how) and add extra waste for curves — curves eat material.

Ready to order? Enter your dimensions in the cubic yard calculator for yards, tons, and bag counts in one step — or get the instant answer on the coverage calculator page.