Free Online Calculators
Calculate volume, weight & bags for garden soil
Whether you're filling a raised bed, refreshing potted plants, or landscaping your entire backyard, one question always comes up: How much soil do I actually need? Buying too little means a second trip to the garden center. Buying too much means wasted money and a pile of dirt you don't know what to do with. Our free soil calculator gives you a precise answer in seconds – no math skills required.
The soil calculator determines the exact amount of soil you need based on the dimensions of your planting area. It calculates:
This means you know exactly how many bags to pick up at the store or whether a bulk delivery makes more economic sense for your project.
You can also adjust the bulk density of the soil if you're working with a specific substrate. Potting mix, raised bed soil, and garden soil all have different densities, and this affects the weight calculation significantly.
The core formula is straightforward: Volume = Length × Width × Depth. For a rectangular raised bed measuring 6 ft × 4 ft (approx. 1.8 m × 1.2 m) with a 12-inch (30 cm) depth, the volume works out to about 648 liters. At an average bulk density of 750 kg/m³ for garden soil, that translates to roughly 486 kg in weight – or approximately 32 bags of 20-liter soil.
For circular areas such as round flower beds or container pots, the calculator uses the formula Area = π × radius². Just enter the diameter and the tool handles the rest automatically.
Garden soil is heavier than most people expect. A single cubic meter can weigh between 700 and 900 kilograms. Many homeowners make the mistake of overloading their car or underestimating how many trips they'll need. The average family car has a maximum load capacity of around 400–600 kg – meaning even a moderate amount of soil can exceed safe limits.
Beyond logistics, accurate calculation helps with budgeting. Bagged soil is convenient but tends to cost more per kilogram than bulk delivery. By knowing your exact volume requirement, you can decide whether ordering in bulk is worth the delivery fee – which is often the case for projects over 1–2 m³.
Different soil products have very different weights per volume unit. Here are some common examples:
Our calculator lets you customize the density value to ensure the weight estimate is as accurate as possible for the specific soil product you're using.
The soil calculator is useful for a wide range of gardening and landscaping projects:
Using our free calculator before purchasing ensures you avoid costly mistakes – both overspending on excess soil and the frustration of running short mid-project.
It depends on the size of your raised bed. A common 2 m × 1 m raised bed filled to 40 cm deep needs approximately 800 liters of soil. Enter your specific dimensions into our soil calculator to get an exact answer tailored to your project.
On average, garden soil weighs between 700 and 900 kg per cubic meter. Lighter mixes like raised bed or potting soil weigh considerably less (300–500 kg/m³) due to high organic content and added perlite or vermiculite.
Simply enter your area dimensions and desired soil depth into the calculator, then select your bag size (20 L, 40 L, or 50 L). The tool will instantly show you how many bags to purchase, including a small buffer recommendation.
Generally, bulk soil is cheaper per kilogram than bagged soil. Delivery typically becomes economical at volumes of 1 m³ or more. For smaller projects, bagged soil remains more practical and convenient despite the higher unit cost.
Absolutely. Just adjust the bulk density to match your material – approximately 1,500 kg/m³ for sand and 1,400–1,700 kg/m³ for gravel. The same formula applies to any granular material used in garden or landscaping projects.