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Topsoil Calculator

Estimate the volume and weight of topsoil needed to cover an area to a given depth.

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Enter Length (m), Width (m), Depth (cm) and the Topsoil Calculator works out Volume, Weight straight away. For instance, with Length (m) = 5, Width (m) = 3 and Depth (cm) = 15 it returns Volume = 2.25 m³ and Weight = 2.925 t.

How to use it

  1. Enter your values: Length (m), Width (m), Depth (cm).
  2. Read the result instantly: Volume, Weight.

Frequently asked questions

What does the Topsoil Calculator actually compute?

It takes Length (m), Width (m) and Depth (cm) and derives Volume and Weight from them. The calculation is live as you type, so the result updates on every change.

What information do I need to provide?

3 values: Length (m), Width (m) and Depth (cm). Nothing else is required — no account, no file upload.

Can you show a worked example?

With Length (m) = 5, Width (m) = 3 and Depth (cm) = 15, the calculator returns Volume = 2.25 m³ and Weight = 2.925 t. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

What happens if I enter larger values?

It moves a lot. Using Length (m) = 5.5, Width (m) = 3.3 and Depth (cm) = 17 instead, Volume goes from 2.25 m³ to 3.086 m³ — which is why it is worth testing a few scenarios rather than trusting a single figure.

What does it give for smaller values?

Scaled down to Length (m) = 4.5, Width (m) = 2.7 and Depth (cm) = 14, Volume comes out at 1.701 m³. The relationship is worth checking at both ends before you rely on a single result.

When would I actually use this?

Planning a bed or a lawn: how much soil to order, how much feed to spread, how far apart to plant, and when the last frost is likely.

What is the most common mistake?

Taking the figure for a promise. Soil, mulch and compost are sold by volume, so a depth you did not think about changes the order threefold; a frost or harvest date is a long-run average, not a guarantee. Both say where to start, not what the season will do.

What is the difference between the Topsoil Calculator and the Mulch calculator?

This one returns Volume and Weight; the Mulch calculator returns Volume (m³) and 50 L bags. That is the whole difference — open the one whose figure you need.

Where do the figures come from, and how current are they?

Volumes and spacings are exact geometry. Frost dates come from long-run meteorological averages for the region, and a garden's own microclimate can shift them by a week or more in either direction.

Further reading

All guides →
How-toHow Much Topsoil Do I Need? A Simple Volume GuideWork out how much topsoil to order from your area and depth — volume in cubic yards, plus the weight in tons so your delivery arrives right.GuideMulch Depth Is the Whole Answer — and It Is a Trade-OffTwo to four inches, and the right end of that window depends on the material: bark takes 3, screened compost takes 1 to 2, and gravel takes 1. Here is the depth trade-off, the settling nobody buys for, and the bag conversion where the count goes wrong.How-toHow Much Sand Do I Need? Volume and Weight Made EasySize a sand order from area and depth: get the volume in cubic yards and the weight in tons for a bedding layer, sandbox or base course.How-toHow Much Fertilizer a Lawn Actually Needs (You Are Buying Nitrogen, Not Bags)The same 2,000 sq ft lawn at the same 1 lb of nitrogen per 1,000 sq ft takes 40 lb of a 5 percent blend or 4.3 lb of urea. Target nitrogen, not product — and read the bag count as shopping, not spreading.ExplainerThe Compost Carbon-to-Nitrogen Ratio: What 30:1 Means and Why Your Bucket Cannot Measure ItA compost heap wants 25 to 30 parts carbon to one part nitrogen by dry weight. Cardboard is 350:1, grass clippings 17:1. Here is the materials table, one mix worked through to 28:1, and why the volume rule of thumb is a different measurement entirely.ExplainerHow to Read an NPK Fertilizer Label (Two of the Three Numbers Are in Disguise)10-20-10 does not mean 10 percent phosphorus. The second and third numbers are oxides, so a 50 lb bag holds 4.4 lb of actual phosphorus, not 10. Here is what each number really measures and how to turn it into a rate.