Most shops know their labour rate to the dollar. Ask what the chemicals on a single car cost and you usually get a shrug and a round number. That guess gets expensive in October, when salt season starts, the wash bay runs all day, and every jug on the shelf drains faster than it did in July.
Detailing chemical cost is simple to work out once you stop thinking in bottles and start thinking in ounces. The price is on the invoice. The pour is something your team can measure in a week. Multiply the two and you have a number you can defend on a quote.
How to calculate detailing chemical cost per car
Start with price per ounce. Take the invoice price and divide it by the ounces in the container. Our bottles are 16oz, and the gallons are US gallons of 128 fluid ounces, eight times the bottle.
Then find ounces per car, measured in your own bay for each service you sell. Multiply price per ounce by ounces per car for every product the car touches and add the lines up.
Here is the first half with a real product. Foam Wash | pH Neutral is $21.99 for the 16oz and $45.99 for the gallon. Divided out, the bottle costs about 137 cents an ounce and the gallon about 36 cents. Bought in bottles, the same pour costs almost four times as much.
Bottle or gallon: the price per ounce gap
The gap between sizes differs by product. Live prices, with price per ounce rounded to the nearest cent:
- Glass Cleaner | Clean+Protect: $20.99 bottle at about 131 cents an ounce, $36.99 gallon at about 29 cents.
- Enzyme | Spot and Stain Remover: $19.99 bottle at about 125 cents, $37.99 gallon at about 30 cents.
- IMPRESS | Interior Cleaner and Protectant: $28.99 bottle at about 181 cents, $51.99 gallon at about 41 cents.
- Eco One | Waterless and Rinseless Wash: $28.99 bottle at about 181 cents, $79.99 gallon at about 62 cents.
- Fuego | 2 in 1 Wheel Cleaner and Iron Remover: $28.99 bottle at about 181 cents, $102.99 gallon at about 80 cents.
- Ultra Dress | Water Based Dressing: $28.99 bottle at about 181 cents, $115.99 gallon at about 91 cents.
Glass, interior and wash products show the widest spread, with the gallon at roughly a quarter of the bottle cost per ounce. On Ultra Dress it is about half. Every product we carry in both sizes is cheaper per ounce in the gallon, so the real question is which gallons empty fast enough to justify the cash.
Which gallons to stock first, by station
The product with the most pours per day goes to the gallon first. Tap a station.
Start here
If every car that comes in gets washed, this is the jug with the most pours, so the gallon pays back first.
Best for
Salt season wheel work. One product covers wheel cleaning and iron removal, so it is one line on the cost sheet.
Best for
Shops that do an interior wipe on most tickets. The gallon brings the cost per ounce down to under a quarter of the bottle.
Best for
Winter maintenance washes when the outside tap is shut off. Worth the gallon once rinseless jobs are on the schedule every week.
Measure the pour before you price the job
Price per ounce is half the formula. The other half lives in your bay, and it changes with the tech, the sprayer, the vehicle and how dirty it rolls in.
The easiest fix is a one week log. Mark the level on each working jug on Monday, count the cars through each service, and read the jug again on Friday. Ounces used divided by cars served is your real ounces per car figure.
Run it separately for each tier you sell, since a maintenance wash and a full detail touch different products in different amounts. Post the numbers at the dilution station so new hires pour the same way.
High season and low season chemical spend
The formula stays the same all year. The inputs move. In the busy stretch the jugs turn over quickly, which is when gallons make the most sense.
Salt season changes the mix more than the total. Wheels and wheel wells carry more of the work, so Fuego and Infinite Shine | Tires, Wheel Wells, Suspension climb up the cost sheet. Once the hose freezes, Eco One takes over from the foam cannon on maintenance washes. If you want the customer side of that switch, our post on waterless vs rinseless washing when the hose is frozen covers it.
When bookings thin out, a gallon that sits half full for two months is cash on a shelf. Keep gallons for the products you pour daily and run the occasional ones from 16oz bottles until volume returns.
Putting chemical cost on the invoice
Some shops add a shop supplies line. Others build chemical cost into the package price. Either works if the number underneath is real.
Coatings and polishes need their own treatment because they are sold by the bottle. UNO | Ceramic Coating is $72.99 for 50mL, DOS | Ceramic Coating is $115.99 for 50mL, and SPARTA | 5 Year Pro Ceramic Coating is $315.99. Divide the bottle price by the vehicles your installer actually gets from it, then add prep such as Wipe | Panel Prep Spray at $72.99 a gallon. Our guide to UNO, DOS, TRÉ and STAK lays out the coating range.
Chemical cost questions from shop owners
How much should chemicals cost per car in a detailing shop?
There is no single right figure, because it depends on your services, your pour and your vehicles. Work it out from price per ounce times measured ounces per car, product by product.
Is buying by the gallon always cheaper?
Per ounce, yes, on every product we sell in both sizes. The catch is cash and shelf space. Buy gallons for the products you pour daily and keep 16oz bottles for the ones you reach for now and then.
Should I charge a shop supplies fee?
That is a pricing decision for your market. Either way, base it on your measured cost per car.
How do I work out ceramic coating cost per car?
Divide the bottle price by the vehicles your installer gets from it, then add prep and polishing products. Track it per job, since vehicle size changes how far a bottle goes.
Does chemical spend change in winter?
The product mix does. Salt months put more weight on wheels, wheel wells and rinseless washes once outdoor water is off. Total spend follows your bookings, so log it by month.
Run the jug log this week, before the salt trucks are out every morning. A few days of honest numbers will tell you which gallons belong on the shelf and what each service really costs.
For the wash bay
Foam Wash | pH Neutral, Gallon
$45.99 · about 36 cents an ounce · ships from Kitchener, Ontario
Add to cartAlso in this post: Fuego Gallon, $102.99 · IMPRESS Gallon, $51.99 · Eco One Gallon, $79.99