Loam Calculator | How Much Sandy Loam You Need

Are you going to start a new landscaping project? Or working on a garden or lawn you already have. Either way one thing is certain — you need to calculate your soil.

In this post I’ll answer every question you have about loam.

Because I know what’s in your head right now.

• How much loam do I need?
• How many cubic yards should I order?
• What depth works for grass and what works for a garden?
• Should I use screened loam or sandy loam?
• And why does every supplier keep asking about cubic yards?

Confusing — I know. But don’t stress. This guide covers all of it.

Loam calculation is simple once you get a few basics down.

• What loam is?
• How to calculate it?
• What its differences types.
• Which one suits your project.
• How deep to go.
• And what it will cost you

Let’s get into it.

What Is Loam Soil?

Loam is a balanced mix of sand, silt, clay, and organic matter.

Good loam feels soft and crumbly in your hand and slightly moist. It drains well but still holds nutrients and water at the same time. That balance is exactly why gardeners, landscapers, and project owners like it.

Here’s what it actually does for you.

• Grass grows thicker.
• Roots go deeper.
• Water drains properly instead of pooling.
• Plants absorb nutrients better.
• And those compacted soil problems you’ve been dealing with? They start to go away.

If your yard is hard clay or dry and sandy, adding loam will make a visible difference. You’ll notice it faster than you’d expect.

Types of Loam Soil

Before you order, know which type of loam your project actually needs.

1. Screened Loam

This is topsoil that has been filtered to remove rocks, roots, debris, and large clumps. It’s the most commonly used type and for good reason.

It works well for preparing a lawn, filling an uneven yard, and general landscaping and garden projects. Spreads smoothly, easy to work with, and ideal for most residential jobs.

2. Sandy Loam

Sandy loam has more sand particles in the mix. That changes how it behaves in the ground.

• Drainage is faster.
• Airflow through the soil is better.
• And waterlogging becomes much less of a problem.

It works best for vegetable gardens, raised beds, wet areas, and plants that don’t like sitting in soggy soil. Roots expand easily through it which is why a lot of gardeners prefer it for growing food.

3. Lawn Loam

This one is made specifically for grass. It has compost and extra nutrients blended in to support seed germination, sod installation, and thick green turf growth.

If you’re building a new lawn from scratch, lawn loam is worth the extra cost. You’ll see the difference in how the grass establishes and fills in.

How to Calculate Loam the Right Way

In the US loam is sold by the cubic yard. So that’s the number you need before you call any supplier.

Here’s how to get there step by step.

Step 1 — Measure Your Length and Width

Work in feet. Say your area is:

• Length = 20 ft
• Width = 15 ft

Multiply them together: 20 × 15 = 300 square feet

Step 2 — Convert Your Depth to Feet

Depth is usually measured in inches. Here’s a quick conversion:

• 2 inches = 0.167 ft
• 4 inches = 0.333 ft
• 6 inches = 0.5 ft

To convert any depth: Inches ÷ 12

Step 3 — Find Your Cubic Feet

Multiply your area by your depth: 300 × 0.333 = 99.9 cubic feet

Step 4 — Convert to Cubic Yards

There are 27 cubic feet in one cubic yard. So divide: 99.9 ÷ 27 = 3.7 cubic yards

Round up and you need about 4 cubic yards of loam.

Most projects stay within 6 inches of depth. I’ve already converted the common depths to feet above so you don’t have to do it yourself.

Quick Coverage Chart

People always ask — how much area does 1 yard of loam cover? Here’s your answer:

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One small mistake in your measurements will throws the whole estimate off. So before you order anything, go back and recheck your length and width. Just that one extra minute saves you from a wrong ordering.

How Much Loam Depth Does Your Project Actually Need?

1. New Lawn: Always go with 4 to 6 inches of loam. That gives roots enough space to establish properly and the grass will grow more healthy.
2. Overseeding an Existing Lawn: You only need 0.25 to 0.5 inches here. Any more and you risk smothering the grass that’s already there.
3. Vegetable Garden: Vegetables need deep soil. Add depth 6 to 8 inches, especially for tomatoes, carrots, peppers, and root crops. They need that depth to grow properly.
4. Raised Garden Beds: 8 to 12 inches is the recommendation here, sometimes more depends on what you’re growing. Sandy loam mixed with compost works really well in raised beds.
5. Yard Leveling: If your lawn is uneven, work out the average depth across the area.

For example:

• Highest dip = 4 inches
• Lowest dip = 0 inches
• Average depth = 2 inches

Generally 0.5 to 1 inch is the common recommendation for leveling. Use that average number in your calculation.

Cost Of Loam Soil — Bags, Bulk, or Truckload. What Makes More Sense?

Cost depends on how you’re buying — bags or bulk. And that depends on your project. Your lawn, your garden, your depth, whether you’re doing a touch up or starting fresh. It all comes down to volume.

One more thing worth thinking about. Your estimate might work out to a truckload in cubic yards but a truck simply can’t reach your area. That affects your choice too.

If you’re filling an existing lawn or a flower bed, bags are a reasonable option. Easy to find, easy to deliver, easy to handle.

But when your project gets bigger, bags get expensive fast. At that point bulk is the smarter call. Using bags by the dozen while your job needs cubic yards just doesn’t add up.

A simple way to think about it:

• Small project → bags
• Medium or large project → bulk loam
• Big landscaping work → truckload delivery

Whatever you choose, get your calculation right first. That one step stops you from wasting money on extra soil you don’t need — or from running short and having to order again.

Common Loam Calculation Mistakes

1. Wrong measurements Double check before you order. Mixing up inches, feet, and yards is more common than you’d think and one wrong number throws your whole estimate off.
2. Forgetting compaction Loose loam settles after you spread it. If you don’t account for that, you won’t end up with the depth you planned for.
3. Ordering the exact amount Never order to the exact number. Always add a little extra for waste and settling. You’ll need it.
4. Ignoring soil quality Cheap loam feels good until you start using it. Poor quality loam comes with rocks, weed seeds, clay chunks, and debris mixed in. Good screened loam costs a bit more upfront but saves you a lot of headaches later.

FAQs

How do I calculate how much loam I need?

Measure your length, width, and depth. Multiply all three together to get cubic feet. Then divide by 27 and you have your cubic yards. That’s the number your supplier needs.

How much does 1 yard of loam cover?

Depends on your depth. At 3 inches deep one cubic yard covers around 108 square feet. The deeper you go the less it covers.

Should I order extra loam?

Always. Add 10 to 15 percent on top of your number. Loam settles and compacts after spreading and you don’t want to run short halfway through the job.

Final Thought

Loam calculation feels intimidating at first. But once you understand the formula it’s really not hard as you thought.

The most important thing is getting your measurements right. Everything else follows from that. Take those measurements, run them through the loam calculator, and you get a clear number — cubic yards, bags, whatever you need.

Measure twice. Calculate once. Pick the right soil for your project.

Now go enjoy your garden.

 

Daniel

Founder & Editor – TopSoilCalcOnline.com

Daniel is the founder and primary editor of TopSoilCalcOnline.com, a practical resource built to help homeowners, landscapers, and contractors accurately calculate topsoil, compost, and soil mix requirements. With hands-on experience in lawn preparation, raised beds, topdressing, and bulk soil planning, Daniel focuses on turning complex volume calculations into simple, reliable tools. Every calculator and guide on this site is designed to reduce material waste, prevent over-ordering, and help users plan landscaping projects with confidence and precision.