How Do You Measure for Concrete Yardage?

The area between forms is measured in feet and inches while the volume of concrete is measured in square yards.

Concrete, whether it is ready-mix or delivered from a plant, is measured in cubic yards in the United States. Concrete forms are measured in square feet and inches. In order to determine the volume of concrete required to fill footer, wall patio, porch or slab forms, the area square foot and inch measurement between the forms is converted to cubic yards. Both the measurement of the forms and the conversion of those calculations into square yards merely require simple mathematics.

Things You'll Need

• Tape measure

Instructions

1. Measure the depth of the form. Measure from the top of the form to the ground. Take several measurements in several different places - in case the excavator did not finish to grade - and take the average. Measure in inches, not feet and inches.

2. Measure the length of each outside form and each inside form when calculating yards for footers and walls. Take the average of the two numbers. For example, if the combined lengths of the outside forms are 100 and the combined lengths of the inside forms are 90, the average is 95. Another method -- and a faster technique -- is to measure the lengths of the center-lines between the outside and inside forms and combine them. Again, measure in inches, not in feet and inches. Measure the width between the forms. Width is simply the distance from the inside face of the outside form across to the opposing face of the inside form.

3. Multiply the depth of the forms by the length. For example: 744 inches -- 62 feet of length -- multiplied by 9 inches of depth equals 6696 square-inches. Measure the length and width of the forms of a pad, patio or deck. There are no inside forms. Measure the depth of the forms. Multiply the sum of the length by the width.

4. Convert square inches into square feet. Divide the length times width times depth sum and divide by 144 -- the number of square inches in a square foot. For example: 6696 divided by 144 equals 46 feet and 6 inches. Divide that sum by 27. There are 27 square feet in one cubic yard. The sum -- for this example is 1.72 yards of concrete. Simply, the formula is: form length multiplied by width multiplied by depth -- in inches -- divided by 144 and again by 27.

References

• SchmitzMix.com: How Do You Measure for Concrete Yardage