What is the Matrix?

The first step in understanding how to properly use a matrix for hail estimation is to understand exactly what it is. First and foremost, it is a guide. A guide, which should be used for reference only. Since no two hail damaged vehicles have the exact same damage, variations will always occur. These variations range from location of damage, size of damage, extent of damage and many others, which factors we will discuss in more detail later and are referred to as “add on’s”. (see bottom of page) Another variation which must be considered is the PDR technician who will be repairing the vehicle. Like the damaged vehicle, no two technicians are alike. PDR is an art, and like most high skilled trades, the more educated and time vested into the trade, the more proficient the technician. All of these variations come into play and should always be taken into consideration when appraising any hail damaged vehicle.

The matrix itself is a chart which has broken the vehicle down into panels. Every panel has its own line on the matrix and each panel is written individually. When all the panels are written, the total of these panels are added to total of the add on’s, to create a final PDR cost. Let’s go through the steps of creating an estimate together to thoroughly explain this process.

Step 1- Clean the vehicle

The first step is cleaning the vehicle. Be sure the vehicle has been freshly washed. Avoiding this step will cause damage to be missed and create an inaccurate estimate.

Step 2- Proper lighting

In order to get achieve an accurate damage inspection the vehicle must always be inside and proper lighting must be used. The best light source for this is the same lighting used by a professional PDR tech during the repair process. A light strip on a stand with enclosed LED lights is ideal. If this is unavailable a fluorescent fixture on a stand will also work. Lights should be mobile and be able to adjust to the proper positions for viewing each panel individually. Any person responsible for appraising hail damage on a consistent basis should have a light in their inventory for use at all times.

Step 3-Calculating dent sizes

All current matrices use the US coin to determine the size of a dent. The sizes are dime, nickel, quarter and half dollar. There are magnets available just for this use which aid in recognizing the correct size. If you don’t have magnets, an actual coin will do. The correct procedure is to place the coin over the dent. If any part of the dent still shows, including a crown caused by the dent, use the next size coin until it completely covers the damage. If you have reached the half dollar size dent and it still does not cover the damage, this dent is now classified as over-sized or larger. We will get into those two ad on’s later.

Step 4- Creating the estimate

Most matrices are created with the first panel being the corner of the vehicle, the fender, with each following line on the matrix being the panel next to the fender and so on. This makes it easier to walk around the car in a fluid motion without having to move back and forth around the car. Let’s start at the left fender. With the light positioned perpendiculer to the panel, which allows the dents to show up in the reflection, begin counting the dents. Always move the light to adjust to the panel when the contours of a panel shift. Not doing this will lead to missed dents and an incorrect appraisal. Once you have counted the dents, locate the “left fender” line on your matrix. Walk down the category which contains the dent count for your vehicle. This fender had 19 dents. This panel would go to the 16-30 category, since 19 falls in between those numbers. Do not circle anything yet. Now look at the 19 dents again. Locate the biggest dents on the panel. Using the dent magnets or coin and calculate which size they are. If the biggest dents are quarter, then the damage on that panel is considered quarter for all. If there are dents that exceed the half dollar, these should be counted and considered oversize, as we mentioned earlier. At the end of that line of the matrix, write “OS” (for oversized) and how many. Example, OS 3 for 3 oversized. The end result for the fender is 19 quarters with 3 oversized. Continue this process on each panel making sure to always position the light correctly and note all oversized and larger dents.

Step 5-R&I (recognizing what trim needs removed to create access for repair)

While writing the PDR damage on the estimate, it is important to take note of how the damage will be accessed, or R&I (remove and install) Most of us understand the obvious items which need to be removed, however there are other items needing removed, which often get over looked. Headlights, tail lights, hood pads, deck lid trim, headliners and sunroofs are common items seen on a PDR estimate. Hoods and deck lids should also always come off for a repair to insure thorough cross checking. Other items which should be considered on a car by car basis depending on the vehicle and the extent of damage are belt moldings, interior door trim, mirrors, grilles, rear hatches on SUV’s rear glass on trucks not having a sliding window, camper shells, truck bed tool boxes, bed caps, fender liners, interior quarter panel trim and spoilers. Any item which impairs access for a PDR tool to reach the damage. Keep an eye out for access issues when doing your dent count on each panel to avoid backtracking.

Step 6- “Add on’s”

Add on’s are additional items which must always be considered when estimating hail. Access to a panel, types of metal and the process of repair itself are just a few of the details which should never be looked over. Here is a list of add on’s to always look for.

1- Uniside/Rail, add additional charge – These panels have almost no access and therefore require glue pulling repairs. These repairs require more effort and time. A proper appraisal should have a additional charge mark up on all rails and uniside panels

2-Aluminum, add additional charge – Aluminum panels do not have the same properties as sheet metal. Sheet metal has what is referred to as a “memory”, It will conform back to its original shape when the proper techniques are used. Aluminum will not. It takes much more assertion and effort to regain its shape. It is for this reason many aluminum panels are replaced. However, a highly skilled PDR technician will have a high amount of success in repairing these panels. Therefore a additional charge mark up on aluminum is always required.

3-HSS (High strength steel), add additional charge – Same principles as aluminum

4-ULHSS ( Ultra light high strength steel), add additional charge – Same principles as aluminum and HSS

5-Inaccessible panel add additional charge – Panels which are inaccessible create a higher level of difficulty This leads to longer repair times and usually glue pulling as well

6-Tall roofs, add additional charge -Tall roofs on SUV’s and pick up trucks are more difficult to repair for both distance of access and reach capabilities 7-Ribbed roof, add additional charge – These roofs make crosschecking a repair extremely difficult due to the ribs obscuring the view of the technician. These are some of the more difficult panels to repair on a vehicle

8-Extra large panel, add additional charge – Extra large panels are as difficult as the tall roofs with access and distance from repair being a key factor

9-Double panel, add additional charge – There are many panels which are double paneled, which limits the ability of a tool being placed on the damage. Braces, honey comb hoods and most Honda roofs with sunroofs are examples of this

10-Glue pull, add additional charge – Same criteria as uniside and rails

11-Oversize dents – Oversize dents are dents which are slightly larger than the half dollar size dents. All oversized dents should carry a premium and be priced individually and accordingly by the technician repairing the vehicle

12- Double Oversize dents (Hen egg)– double oversize dents are dents which are slightly larger than oversized dents. Double oversized dents should carry a premium and be priced individually and accordingly by the technician repairing the vehicle

13-Deep/sharp dents – Same criteria as oversize

14-Luxury vehicle (higher liability), add additional charge – High end vehicles should carry a premium on repairs due to a higher liability exposure on the technician repairing the vehicle

15-Corrosion protection – All vehicles repaired by the PDR process should have corrosion protection applied to each panel repaired.


If the proper procedures are taken, you should be able to write an accurate appraisal. However, as stated in the beginning, this is only a guide. To insure higher accuracy it is best to have the PDR technician who will be repairing the vehicle assist in the process.


Download the PDRN Matrix