How to calculate cubic yards of concrete from satellite

Ordering a ready-mix concrete truck is stressful. If you under-order by a half-yard, you are stuck with a "short load" fee (usually hundreds of dollars) just to get the truck to come back with the final wheelbarrows of concrete. If you over-order by 3 yards, you are literally pouring money down the drain.

Historically, concrete contractors would drive to the property, pull out a measuring tape, and spend 45 minutes manually staking out the pour to calculate the volume. Now, you can run the math instantly from your office.

Step 1: Finding the 2D Footprint

Everything starts with Square Footage. To calculate volume, you first need the 2D surface area of the driveway, patio, or slab.

Using a satellite mapping tool, trace the perimeter of the existing driveway (or the grass if you are pouring a new patio). The software instantly calculates the square footage. Let's assume you trace a driveway and it comes out to exactly 800 Square Feet.

Step 2: The Volume Conversion Formula

Ready-mix concrete is sold by the Cubic Yard. To convert Square Footage (2D) into Cubic Yards (3D), you must factor in the depth (thickness) of the slab.

A standard residential driveway is poured at 4 inches thick. Commercial aprons are often 6 inches thick. Let's run the math for a standard 4-inch pour:

First, convert your 4-inch depth into feet:
4 inches ÷ 12 = 0.333 feet

Next, multiply the area by the depth to get Cubic Feet:
800 sq ft × 0.333 ft = 266.4 Cubic Feet

Finally, divide by 27 (because there are 27 cubic feet in a yard):
266.4 ÷ 27 = 9.86 Cubic Yards

Step 3: The Waste Factor (The Most Important Number)

If you order exactly 9.86 yards for this job, you will run out. Period.

The subgrade is never perfectly level. A tiny dip in the gravel base means that a 4-inch slab is actually 4.5 inches thick in certain spots. Furthermore, a little bit of concrete always gets left inside the drum of the truck, or spills over the forms.

You must apply a Waste Factor. The industry standard is 10%.

9.86 yards × 1.10 (10% waste) = 10.84 yards

You round up to the nearest quarter yard. You call the ready-mix plant and order exactly 11 yards.

Stop Doing Manual Math

The process outlined above works perfectly, but doing it on a calculator while talking to a customer on the phone is how mistakes happen.

That is why we built the Concrete Volume Engine. Once you have your satellite square footage, plug it into the widget above. Select "4 Inches" from the dropdown, slide the waste factor to 10%, and it instantly spits out your final Cubic Yardage.

You can now quote a $15,000 driveway replacement while sitting in your truck.