When pouring concrete for a driveway, it is very important to accurately estimate the amount of concrete you will need to buy. Purchasing too much will leave you holding onto a quantity of concrete with no where to place it. Not having enough will leave your project short and may lead to discrepancies or faults in the construction. Here are a few steps that will help you closely estimate the amount of concrete you need for the job.
Things You'll Need
 Calculator
 Measuring tape
 Wooden stakes
Measure the Square Footage

Determine the exact area where you want to build your driveway.

Use stakes to establish the boundary so that you can easily measure the distances without losing track of where you started.

Once you have these numbers, multiply them together to get the square footage. For example, if the length is 20 ft and the width is 15 ft, the square footage is 300 ft. (20x15 = 300).

In the event that there are uneven or oddly shaped portions of the area, measure these zones separately and add the separate square feet together.
Purchase Products

Once the square footage is determined, you can place an order for products.

Concrete supply company Quikrete has a calculator online to help determine the amount of concrete needed for your project. Simply type in the square footage you have determined and the site will approximate how many bags of product needed to pour either a 4" or 6" slab. (See References 1.)

This calculator can only provide an estimate based on your calculations and does not take into account any areas that may not be level and may require more or less product.
Tips & Warnings
 Check and recheck your measurements to ensure accuracy.
 Before pouring concrete, level out the area so that the concrete pours evenly.
 Before beginning any home improvement project, ensure that you are in compliance with any local ordinances regarding building and construction.
 Avoid pouring more concrete than you can work with at any one time.