A 4×8 ft raised bed at 12 inches deep takes 32 cubic feet (1.2 cubic yards) of topsoil — order 1.3–1.4 cubic yards to allow for settling. Bulk topsoil typically costs $30–$60 per cubic yard plus $50–$100 delivery, so about $42–$84 plus delivery, versus $96–$240 for the equivalent ~24 bags.
Run your exact dimensions through the free Topsoil Calculator before you order.
How Much to Order (With Settling Allowance)
The base math: 4 ft × 8 ft × 1 ft = 32 cu ft, and 32 ÷ 27 = 1.185 → ≈ 1.2 cubic yards. But fresh topsoil settles and compacts 10–20% once watered:
- 10% settling: 1.2 × 1.10 = 1.32 → order 1.3 cu yd.
- 20% settling: 1.2 × 1.20 = 1.44 → order 1.4 cu yd.
Most suppliers sell in whole or half yards, so a 1.5-cubic-yard order is the practical sweet spot for a 4×8 bed at 12 inches deep. For a 6-inch bed, order about 0.75 cu yd; for 18 inches, about 2.2 cu yd.
Bulk vs Bags: Cost Comparison
Here are the real numbers for the same 4×8 bed (12 in deep):
- Bulk topsoil: 1.4 cu yd × $30–$60/yd = $42–$84, plus delivery typically $50–$100 → $92–$184 total.
- Bagged soil: ~24 bags of 1.5-cu-ft soil × $4–$10 = $96–$240, and you haul it all yourself.
Bulk is usually the cheaper route for a bed this size, and the gap widens if you have multiple beds or neighbors splitting a delivery. Bags win when you have no driveway access for a dump truck, only need a small amount, or want a specific blended mix sold only in bags. Delivery minimums vary — some suppliers deliver as little as 1 yard, others require 2–3 yards minimum, so ask before planning your order.
Ordering Bulk: What to Ask the Supplier
A quick phone call avoids the most common bulk-order disappointments:
- “Is it screened?” Screened topsoil costs a bit more but arrives free of rocks, roots, and trash. Unscreened is fine for filling low spots — not for a garden bed.
- “What is the minimum delivery?” Many suppliers require 2–3 cubic yards minimum. At 1.4–1.5 cu yd you may need to round up to the minimum or split a load with a neighbor.
- “What is the delivery fee and where will you dump it?” Fees typically run $50–$100, and the truck needs driveway access. Ask how far the dump pile will be from your bed — shoveling soil 50 feet is a real workout.
- “Can I see it first?” Good suppliers will show you the pile. Look for dark, crumbly soil — avoid gray, foul-smelling, or overly clayey material.
Topsoil Tips for Raised Beds
- Buy screened topsoil. Screened soil has rocks, roots, and debris sifted out, giving a finer, more workable fill. Unscreened soil is cheaper but can arrive chunky and uneven.
- Don’t grow in pure topsoil. Straight topsoil is often dense and low in nutrients. Mix in compost at roughly a 60:40 or 70:30 topsoil-to-compost ratio for a bed plants actually thrive in.
- Fill in layers. Add soil in 4–6-inch lifts, watering each layer lightly. This settles the soil evenly, removes big air pockets, and gets most of the settling done before you plant.
- Water between layers, not just at the end. Light watering per layer compacts gently without creating a hard crust on top.
- Top-dress with compost after planting. Even a well-mixed bed benefits from a 1–2-inch compost mulch each season — it feeds the soil biology as it breaks down.
Common Mistakes
- Ordering unscreened fill dirt by mistake. “Fill dirt” is for leveling ground, not growing — it’s often clay-heavy, rocky, and nutrient-poor. Specify topsoil when ordering.
- Filling to the brim. Leave 1–2 inches of headroom below the rim so water and mulch stay in the bed instead of washing over the sides.
- Skipping the settling allowance. A bed filled exactly to 1.2 cu yd of fresh soil will sink an inch or two within weeks. Order 1.3–1.4 cu yd (practically 1.5) and save yourself a top-up order.
- Paying bag prices for bulk quantities. Once you need more than about a cubic yard, get a bulk quote — bagged soil is almost never the cheapest path past that point.
FAQ
How much topsoil do I need to fill a 4×8 raised bed?
1.3–1.4 cubic yards for a 12-inch-deep bed (base volume is 1.2 cu yd plus 10–20% for settling). A 1.5-cubic-yard bulk order covers it with room to spare.
Is bulk topsoil or bagged soil cheaper for a 4×8 bed?
Bulk is usually cheaper: roughly $92–$184 including delivery for 1.4 cu yd, versus $96–$240 for the bagged equivalent — and you skip hauling two dozen bags.
Should I mix compost into topsoil for a raised bed?
Yes. Pure topsoil is typically dense and lean — blending in about 30–40% compost gives plants better drainage, structure, and nutrients. A 60:40 or 70:30 topsoil-to-compost ratio is a reliable starting point for most vegetables.
Size your bed precisely with the Topsoil Calculator, then compare pricing details in the complete guide and the cost guide.