One of the most important, if not the most important, aspects of operating a profitable business is knowing what to charge. Many factors go into properly estimating a project such as: Labor Costs, Material Costs, Equipment Costs, Trucking Costs, and more. In this article we will discuss how to properly calculate how much material will be needed for your sealcoating jobs.
The most important number you will need to know for this calculation is 231. Not only is that how many mini marshmallows I can fit in my mouth, that is also the number of cubic inches per gallon. This is vital for sealcoat, crackseal, striping and any other product that uses material purchased by the gallon.
Cubic Inches per Gallon = 231
Now all we need to do is figure out how many cubic inches there are in your job. That is where the second important number comes from: 1,728. Yes, this is how many cubic inches are in a square foot, but more importantly it is how many pushups I can do in a row. (JK… I look like Jack Skellington).
Cubic Inches in a Cubic Foot = 1,728
I’m assuming you are measuring your jobs by the square foot. If that is the case, this becomes really easy to calculate:
Let’s assume you’re doing a 5,000 square foot driveway or parking lot.
Also, we need to know how thick you apply the material. If you squeegee the material it will be different than if you’re spraying. We work with crews spraying at 20 mils and some spraying at 80 mils. For this exercise we’ll assume a 30 mil application rate.
Now that you know exactly how many gallons you can simplify this process to 5,000 square feet at a 30 mil application rate = 93.5 gallons, or 53.5 Square Feet per Gallon. 5,000 Square Feet / 53.5 = 93.5 Gallons.
If your application rate changes from 30 mils to something else, you will need to adjust the above calculation.
Once you have the initial calculation to figure out your coverage rate per gallon, it become very easy to then calculate material needs going forward. You can create a quick reference sheet that shows different application rates and their coverage per gallon. This would allow very fast material usage and estimating.
