River Rock Calculator

This river rock calculator will help you find how much river rock you need for your rock bed, no matter its area and depth. You can also use our tool as a river rock coverage calculator to know the area a specific volume or weight of river rock can cover. We have also equipped this tool with a river rock cost calculator, so you can also quickly know how much your river rock will cost you for your entire project.

In the article, you will learn how to calculate river rock volume and its corresponding weight using the densities of different river rocks. We will also briefly discuss the different types of river rock you can use for your projects. Keep on reading to learn more.

River rocks is the name for gravel and rocks found in the streambeds of natural water channels), like rivers or creeks. These rocks are usually round in shape and have smooth textures due to the friction from the water's continuous flow. They also come in a variety of colors depending on the minerals present in them. In specific locations, we may find many of the same rock types that we can collect and use at home. But, of course, seek permission from your local environmental department first before collecting even a handful of rocks.

Uniformly colored rocks can function as a decorative addition to an aquarium or can even be landscaped together with your mulch and neatly mowed lawn. We can also find river rocks used as riprap rocks or soil covering to avoid erosion and water runoff, or as backfill for french drains. Explore more about french drains thru our french drain calculator.

Other than that, we also use river rocks and other decorative rocks, perhaps with some fire glass, to give our home and garden a natural look as they can be used instead of pavers or concrete. However, the environment needs these stones, too, so we have to know how much river rock we need to purchase to help conserve what we have.

The amount of river rock you need depends on the area you wish to cover with river rock and your desired river rock covering depth. The area and depth of your river rock bed is entirely up to you. So, if you really are planning to add river rock to your landscape, go ahead and measure up the area you wish to cover and we'll help you evaluate how much river rock you need.

Before we proceed to the calculation of the volume and weight of your river rock, let us first explore some of the different river rocks we can choose from. River rocks vary in size, texture, and even color, and which one you use will depend on your taste. Some of these rocks may already be familiar to you, while some may be new:

In our table above, we have also included the densities of these rocks, as we will be using these values to determine the weight of your river rock. Once you've decided which rock to choose, we can already start calculating.

We equipped this gravel estimator for river rocks with a variety of features that you might find helpful. To find how much river rock you need, here are the steps to follow:

1. Select the type of river rock you wish to use. Upon choosing one, our river rock calculator will instantly display the density of that type of rock. Different river rocks have different density values, so their total weight may be different.
2. You can also input the density of your river rock by selecting the Custom option from the list.
3. Enter the dimensions or the surface area you want to cover with river rock and its depth. This will instantly display the estimated volume of your river rock.
4. Decide how much river rock you might waste when applying them to the area. You can also consider this as the contingency if the dimensions you entered in the fields are subject to change.

You are at the right place to find how much area or square footage a certain volume or weight of river rock can cover. You first have to enter the volume or weight of the available river rock you have, whichever value is known for this requirement. Then input your desired river rock depth.

You will then instantly see the area coverage of your river rock. Play around with the calculator to explore which variables you can work out by filling in your known fields and leaving a particular variable empty.

At the very bottom, you will see the river rock cost calculator feature, wherein you can enter the cost of river rock per unit volume or per unit mass to find the total cost of your selected river rock.

Now that we know how to use our calculator, either as a river rock coverage calculator or as a river rock cost calculator, wouldn't it be nice to also know how to calculate river rock's volume or weight on your own? All you have to do is find the volume that you want to fill with river rock by multiplying its dimensions together while considering the percentage of waste you might have, as shown in the equation below:

where:

• $V$ – Volume needed;
• $A$ – Area;
• $d$ – Depth; and
• $c$ – Wastage percentage.

After calculating the needed volume of river rock, multiplying its value by the density, $\rho$, of this river rock will give you the corresponding weight, $W$, of your river rock, like in this equation:

You can check your preferred river rock's density value in the different types of river rock section of this text.

Let's say we want to make a $\small 7.5\text{-cm}$ thick pea gravel (density = $\small 1,\!788\ \text{kg}/\text{m}^3$) walkway with a width of $\small 80\ \text{centimeters}$ (or $\small 0.8\ \text{m}$) and a length of $\small 10\ \text{meters}$. Using the formula we have and considering a $\small 5\%$ contingency or wastage, we estimate our needed river rock volume as follows:

If you need the volume in cubic feet or cubic yards, you can use our volume converter for the conversion. Nevertheless, when using our river rock calculator, you can easily change its units by just clicking or tapping on its units and selecting the unit you want.

Going back to the computations, to know how heavy this volume of pea gravel is, we evaluate its weight using the equation below:

We now know we need more than $1,\!126.44\ \text{kg}$ of pea gravel for our walkway project from our calculation above. 🙂