Waste Tire Enforcement

Determining the Number of Tires

The formulas and tables on this page are intended to assist the inspector in determining the approximate number of tires at a site. Numbers of whole tires are calculated by volume (in cubic yards). Numbers of altered tires (in passenger tire equivalents) can be calculated by volume or by weight. Before determining the number of waste tires, make sure you understand the definitions of waste and other tires. For inspection purposes, only waste tires are counted toward total number of tires allowed.

• Calculate by Cubic Yards
• Calculate by Weight

Calculate by Cubic Yards

Use the following formula based on the length, width, height in feet (obtained by measuring or estimating tire pile size) and convert to cubic yards of tires:

[Length (feet) x Width (feet) x Height (feet)] ÷ 27 = Volume (in cubic yards)

Once you have determined the cubic yards of a tire pile, multiply cubic yards by the tires per cubic yard (tires/cy) as listed in the conversion tables below for whole or altered tires.

Whole Passenger/Light Truck Tires

Storage Type	Height of Tire Pile
(Stored less than 15 years)	(<10 feet)	(10-15 feet)	(>15 feet)
Loose	10 tires/cy	12 tires/cy	14 tires/cy
Barrel	12 tires/cy	14 tires/cy	16 tires/cy
Laced	14 tires/cy	16 tires/cy	18 tires/cy
(Stored 15 years or more)
Loose	12 tires/cy	14 tires/cy	16 tires/cy
Barrel	14 tires/cy	16 tires/cy	18 tires/cy
Laced	16 tires/cy	18 tires/cy	20 tires/cy

Whole Semi-Truck Tires

Storage Type	Height of Tire Pile
(Stored less than 15 years)	(<10 feet)	(10-15 feet)	(>15 feet)
Loose	2.5 tires/cy	2.75 tires/cy	3.0 tires/cy
Barrel	4.2 tires/cy	4.4 tires/cy	4.6 tires/cy
Laced	4.1 tires/cy	4.3 tires/cy	4.5 tires/cy
(Stored 15 years or more)
Loose	3.0 tires/cy	3.5 tires/cy	4.0 tires/cy
Barrel	4.4 tires/cy	4.6 tires/cy	4.8 tires/cy
Laced	4.3 tires/cy	4.5 tires/cy	4.7 tires/cy

Altered Tires

Type	Tires/CY	Description
Sidewalls or treads	20  tires/cy	The photo below shows cut out sidewalls and treads.
Primary shreds	20 tires/cy	Tires that have been run through a shredder one time.
Shreds 2 inches or smaller	40 tires/cy	Tires that have been run through a shredder more than once to create pieces two inches or smaller.
Crumb rubber (less than ¼ inch in size)	NA	Not regulated by the California Department of Resources Recycling and Recovery.

Calculate by Weight

If you know the weight of altered tires, you can convert directly to a number of passenger tire equivalents (PTE).

The California Code of Regulations, 14 CCR Section 17225.770 defines a "passenger tire equivalent" (PTE) as the total weight of altered waste tires, in pounds, divided by 20 pounds. 1 PTE = 1 Waste Tire.

If weight is known:

Total Known Weight (pounds) ÷ 20 pounds = PTE

Note: This information is also found on the back of the Comments Form (CIWMB 183).