Most people will use gravel for one reason or another at least once in their life. Because gravel is relatively inexpensive and can be used for a variety of projects. Though for large projects, concrete is cheaper, for small projects, gravel will do.
If you have the money for gravel, then it can be a fun option with a completely different aesthetic landscape. Though even if you have money, you don’t want to waste it. So here is how you can figure how much gravel you need.
How Much Gravel Do I Need?
This is a question we get a lot. “How much gravel do I need?” Finding out how much gravel you need doesn’t have to be a difficult task. All you need is either a calculator or a little mental math and a measuring tape.
Then, you can figure up how much gravel you need for any project you can imagine. Because in reality, it’s all about finding the volume of the area that you need to feel or “pave” with gravel. The type of gravel doesn’t matter too much.
How To Calculate How Much Gravel I Need
All you need to calculate the amount of gravel that you need is a simple formula. In general, gravel is sold by the cubic yard, so this is the number that we need to find. The formula for this is quite simple.
You will end up following an LxWxH=V formula before converting the end result to cubic yards. It is the easiest to work with feet rather than yards that will be too large or inches, which will be too small. Though any unit works as long as you end up with yards.
Step 1: Find The Square Footage
The first step is finding the square footage. It doesn’t matter if you are digging a deep and narrow hole or a long and wide path. The first thing you do is measure the area and find out how wide and long it is.
So take the LxW=A(area) and save that number. Measure twice or even three times to be sure. It should be two measurements that are converted to feet, rather than inches, as inches are harder to work with than feet.
Note: for non-square areas, you can figure the area of the largest mass and then keep that number. Then find the area of each other smaller area and add all of the results together. For circles, use the formula A = π r². This is radius, times radius, times pi.
Step 2: Find The Depth
After you have that square footage, find the depth. This could be 1-inch or it could be 10-feet. But you should only have to measure it once or twice, making sure to work with the lowest point unless there is a steep incline.
For steep inclines, the math is a bit trickier. To find the volume of an inclined area, you need to find the average depth. To do this, find the shortest point and the tallest point and add them together. Then divide the number by two.
For example, if the shortest depth is 4in and the tallest is 12in, you add the two together to get 16. Then divide it by 2 to get 8. The average depth is 8. More complicated, but still simple in the end formula which remains the same.
Note: convert the inches to feet before using the number to find the volume. Do this by dividing the number in inches by 12.
Step 3: Find The Volume
Finding the volume is quite easy in an area with equal depths and symmetrical surface area. The formula is a simple LxWxH=V where V stands for volume. The entire formula is length times width times height equals volume.
The formula AxH=V is also correct because you multiply the length times width first to get the area which you can multiply by the height. This equals volume. The volume is what you need to find.
Let’s try this out in an example. Let’s say that you have an area that needs to be filled. You find out that it is 20ft wide and 32ft long while being 4ft deep. First, find the area. Which is 20×32=640.
Then you take 640 and multiply it by the height of 4. Then you get 2560. So the volume in cubic feet is 2560. However, there is still one more thing that we need to do.
Step 4: Convert To Cubic Yards
This is the easiest step because it is only one step. Once you find the volume in cubic feet, all you need to do is divide it by 27. This is because there are 27 cubic feet in a cubic yard. So it is easy to figure.
Let’s take that number we just calculated, which was 2560 cubic feet. Divide it by 27 to get 94.8. Because we need to have enough gravel for the area, we round it up to 95. For this area, we need 95 cubic yards of gravel.
How Much Gravel For A Patio?
Finding out how much gravel you need for a patio is one of the most common things that people using gravel need to know. Because gravel is often used for a patio of some sort due to the price and stability.
Patios are fairly easy because they are generally fairly symmetrical. So if you have a space for a patio that is 10ft by 12ft, you first find that the square footage is 120ft. Then, if the depth is 3inches, you convert that to feet, which is .25ft.
Using the formula we learned earlier, you multiple these three numbers, 12×10 is 120. Then 120 times .25 is 30. Since you want to figure how many cubic yards rather than cubic feet you need, you divide that number, 30, by 27.
The end result is 1.11 cubic yards. So you need 1.11 cubic yards of gravel for a patio that is 10ft x 12ft x 3in. This works for any patio especially since 3-4 inches is a good depth for a patio and the length and width do not matter.
How Much Gravel For A Driveway?
The formula for finding the right amount of gravel for a driveway is the same as finding the right amount of gravel for a patio. The difference is that driveways can be long and narrow compared to the more square patios.
However, there are two different ways people use the term driveway. One is used for the path that is driven to the parking spot while the other is used to describe the parking lot. The parking lot is calculated just like the patio.
However, the driveway is a little different. The formula is the same, but it is more difficult to figure because it is often winding. If the driveway is in curves with straight angles, you can just figure the area of each straight stretch
But if it is a curved road, then you can use a simple trick with a garden hose. Lay a garden hose or rope out where you want the path to be. You can even use a stake and rope to measure an exact radius for each curve.
After you have the right path marked with a hose, measure the length of the hose used. Then, you can treat it like a rectangle. Use the hose measurement as the L. Then you just do the simple LxWxH measurement.
How To Buy The Right Amount Of Gravel
Gravel is normally purchased in half-tons or by the cubic foot. Though they are often also measured in pounds. However, the poundage shouldn’t be used for calculations as you can’t rely on poundage, but rather on volume.
To buy gravel by the truckload, you can contact a hardware store or private company. The more common way to buy it is by the bag. Bags of standard gravel come in .5 cubic ft. So if you have a very small area, this is the way to go.
Those bags run about $5. This can add up if you have over 2000cb ft of volume like we had earlier. A better option, in this case, is to contact more private companies or companies that specialize in this.
These companies usually deliver but also usually have a minimum order. So you will have to order at least half a truckload on most occasions. when you order a certain amount, the delivery fees are often waived.
Should I Choose Gravel?
Gravel can be expensive, especially if you need a lot of it. Though the more you buy, the less it is per cubic yard. This is a good thing. But it also means you may end up buying more than you need just to save money.
If you end up with extra gravel, try out some of these amazing projects. We were inspired by limestone gravel, but you can use any type of gravel for most gravel projects, with pea gravel being a favorite for most people
Whatever you do, make sure it speaks to you. Have fun with your project. Because even the process can be enjoyable if you let it be. But we all know, the best part is that moment you finally finish your masterpiece.