Use this calculator to easily estimate how much soil (topsoil) in tons or tonnes, or volume (cu ft, cubic yards or cubic meters) you need for a given gardening project. Given bag size, it also calculates the number of bags of soil you will need.
Calculating how much topsoil you need
Many professional and home gardeners are faced with estimating the amount of topsoil they need to cover a given area. If you are asking yourself how much topsoil do you need for your garden, then our topsoil calculator is of great assistance as it does the math for you in a metric of your choice (suitable if you are living in the US, UK, EU, and others), but you should keep in mind that the results will only be as good as the measurements entered into it.
Also, we use a standard soil density of 100 lbs/ft3 (1600 kg/m3) which may be somewhat different depending on the precise topsoil mixture you purchase. Blended topsoil is usually less dense, and thus fewer pounds of it will be required. The calculation process is:
- Estimate the volume of topsoil needed, using geometrical formulas and plans or measurements of the area.
- Estimate the density of the soil to be used. Standard density for topsoil is around 100 lb/ft3 (1600 kg/m3).
- Multiply the volume by the density (in the same units) to get the soil weight
Volume calculation is a bit tricky if the area you are calculating has an irregular shape. Then you need to divide it in several regularly-shaped sections, calculate their volume and topsoil requirements and then sum them up. In case you end up needing to do this for a large number of sections, you might use our summation calculator. Approximations are also OK in most cases.
Topsoil is usually sold in bags in big retail stores and specialized stores, and in bulk by the ton (or tonne) from companies specializing garden supplies. The topsoil calculator will help you estimate how much of it do you need and will make it easy to compare bulk orderign versus buying by the bag, as you will always see the per ton price.
To determine the number of bags you need, you must know how much soil a bag will yield. Topsoil producers don't have a convention on how to mark their product, so you may know the bag's volume, e.g. 1 cu ft, or 1 cu yd, or you may know it's weight, say, 40 lbs (or 20 liters and 25 kg for the metric system). Our soil calculator supports all of these different types of bags and will make the necessary conversions automatically.
When going to shop for topsoil, remember that the measurements you take will have a margin of error, especially if the terrain is with an uneven depth, so you should consider purchasing 5-6% more topsoil than estimated so you don't run out.
Topsoil (soil, dirt) is important since plants derive most of their vital nutrients from this upper, outermost layer of soil, usually between 2 inches (5.1 cm) to 8 inches (20 cm) deep. It is here that most of the Earth's bio activity occurs - decomposition, excrements, etc. all end up here, and it has the best conditions for most life thus it has the highest concentration of organic matter and microorganisms. The soil is composed of a mix of mineral particles, organic matter, water, and air.
In terms of physical characteristics, soil can sustain its own weight and other internal matter such as water. It's bearing capacity is good, making it a good base for supporting structures above it, up to a point. The strength of topsoil structure decreases with the presence of organic matter, meaning it can bear less weight. Dewatering also has a negative effect on soil skeletal structure and its volume decreases. When sold, it is usually processed and screened to remove rocks and debris from it.
Typical soil composition
|Aluminum||6 - 10%|
|Calcium||1 - 7%|
|Iron||2 - 10%|
|Magnesium||0.1 - 3%|
|Oxygen||44 - 49%|
|Potassium||1.5 - 3%|
|Silicon||22 - 36%|
|Sodium||2.4 - 2.5%|
As you can see some elements composing dirt can vary significantly so make sure to read the label when buying since different types of plants have different needs for nutrients and preferred soil conditions. Some can be strongly adapted to certain conditions and not thrive or even die elsewhere, making the choice of soil crucial for maintaining them in good shape.
What is the density of soil?
The density of typical soil is 100 lb/ft3 (1600 kg/m3). This corresponds to moderately damp consolidated soil (rammed earth) and is the number used in the calculator. When the soil arrives it will be loose and likely have a density of just 75 lb/ft3 or 1200 kg/m3 and will require a larger vehicle to transport.
How much does a yard3 of topsoil weigh?
A cubic yard of typical topsoil weighs about 2700 pounds or 1.35 tons. A square yard of a garden with a depth of 1 foot (30.48 cm) weighs about 900 pounds (410 kg) or slightly less than half a ton. The water content of the soil is assumed to be that of a moderately damp (e.g. freshly dug).
How much does a cubic meter of topsoil weigh?
A cubic meter of typical topsoil weighs 1,600 kilograms 1.6 tonnes. A square meter of garden with a depth of 35 cm weighs about 560 kg or 0.56 tonnes. The numbers are obtained via this soil calculator.
How much is a ton of soil?
A ton of condensed soil is typically about 0.750 cubic yards (3/4 cu yd), or 20 cubic feet. Soil is assumed relatively damp, since adding water can increase or decrease the density of the soil considerably (e.g. if it was raining or if you dig up and leave dirt under the sun so water evaporates).
How much is a tonne of soil?
A tonne of condensed, moderately damp soil typically fills about 0.625 m3 (cubic meters). It can be more or less dense depending on water content and the exact composition.
Ton vs tonne, tons vs tonnes
When calculating weight, make sure you do not confuse the tonne (metric ton) with the ton (short ton). The first is used by all countries in the world, except the U.S. and is defined to be equal to 1000 kg by the international body of standardization. The ton is currently only used in the United States and is equal to 2000 pounds (2000 lbs). The difference between the two is not huge but can add up to a significant number as the amount of soil purchased increases.
Cite this calculator & page
If you'd like to cite this online calculator resource and information as provided on the page, you can use the following citation:
Georgiev G.Z., "Topsoil Calculator", [online] Available at: https://www.gigacalculator.com/calculators/soil-calculator.php URL [Accessed Date: 24 Sep, 2018].