Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Total chemical cost per car
$0.088
Pre-soak cost per car
$0.033
Soap cost per car
$0.014
Wax/sealant cost per car
$0.042
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How to use this
- 1Enter pre-soak concentrate cost ($/gal).
- 2Enter pre-soak dilution ratio (parts water : 1 part chemical).
- 3Enter pre-soak oz used per car (diluted).
- 4Enter soap concentrate cost ($/gal).
- 5Enter soap dilution ratio.
- 6Enter soap oz used per car (diluted).
- 7Enter wax/sealant concentrate cost ($/gal).
- 8Enter wax oz used per car (diluted).
- 9Read your total chemical cost per car on the right — it updates as you type.
- 10Hit Share to keep the scenario or send it to someone.
About this calculator
Chemical cost is typically the second-largest variable cost after labor and water at a car wash, and it's frequently underestimated because chemicals are purchased in bulk (drums or totes) and diluted, making per-car cost non-obvious. This calculator takes your bulk chemical cost, concentrate dilution ratio, and ounces applied per car for each of the major chemical categories used in a typical wash package (pre-soak, soap, wax/sealant, and a drying agent), and rolls them into a total chemical cost per car. Compare that against your wash package price to see true contribution margin before labor, water, and equipment costs.
Worked example
Using the values the calculator loads with:
Inputs
- Pre-soak concentrate cost: 22 $/gal
- Pre-soak dilution ratio (parts water : 1 part chemical): 20
- Pre-soak oz used per car (diluted): 4
- Soap concentrate cost: 28 $/gal
- Soap dilution ratio: 128
- Soap oz used per car (diluted): 8
- Wax/sealant concentrate cost: 55 $/gal
- Wax oz used per car (diluted): 3
Results
- Total chemical cost per car: $0.088
- Pre-soak cost per car: $0.033
- Soap cost per car: $0.014
- Wax/sealant cost per car: $0.042
What each field means
Inputs
- Pre-soak concentrate cost ($/gal)
- The pre-soak concentrate cost used in the calculation, measured in $/gal. Starts at 22 $/gal so you have a working example on load.
- Pre-soak dilution ratio (parts water : 1 part chemical)
- The pre-soak dilution ratio (parts water : 1 part chemical) used in the calculation. Starts at 20 so you have a working example on load.
- Pre-soak oz used per car (diluted)
- The pre-soak oz used per car (diluted) used in the calculation. Starts at 4 so you have a working example on load.
- Soap concentrate cost ($/gal)
- The soap concentrate cost used in the calculation, measured in $/gal. Starts at 28 $/gal so you have a working example on load.
- Soap dilution ratio
- The soap dilution ratio used in the calculation. Starts at 128 so you have a working example on load.
- Soap oz used per car (diluted)
- The soap oz used per car (diluted) used in the calculation. Starts at 8 so you have a working example on load.
- Wax/sealant concentrate cost ($/gal)
- The wax/sealant concentrate cost used in the calculation, measured in $/gal. Starts at 55 $/gal so you have a working example on load.
- Wax oz used per car (diluted)
- The wax oz used per car (diluted) used in the calculation. Starts at 3 so you have a working example on load.
Results
- Total chemical cost per car
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Pre-soak cost per car
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Soap cost per car
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Wax/sealant cost per car
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
What's a typical total chemical cost per car?
Most express tunnels run $0.35-$0.90 in total chemical cost per car depending on how many add-on steps (ceramic sealant, ultra wax, ceramic ppf-safe ceramic ) are included in the package. Basic exterior-only washes sit at the low end; top-tier packages with multiple protectant layers push toward $1.00-$1.50.
How does dilution ratio actually work in this calculator?
A 20:1 dilution means 20 parts water to 1 part concentrate, so a gallon (128 oz) of concentrate makes 128×20 = 2,560 oz of usable diluted product. The formula spreads the concentrate's cost across all of that diluted volume, which is why higher dilution ratios dramatically cut cost per ounce applied.
Why does the top-tier wax package barely move total cost?
Wax and sealant chemicals cost more per gallon of concentrate but are applied in small volumes (2-4 oz per car) and are usually diluted, so even a 'premium' upsell chemical often adds only $0.10-$0.30 per car in true cost against a $5-10 price upsell — which is why ceramic upsells carry very high margin.
Should I include water cost separately?
Yes — this calculator is chemical cost only. Water and sewer cost per car (usually 10-25 gallons for a tunnel wash) should be tracked as its own line item alongside electric for pumps and blowers to get a full variable cost per car.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
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Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Car Wash Chemical Cost Per Car Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/car-wash-chemical-cost-per-car
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/car-wash-chemical-cost-per-car" target="_blank" rel="noopener">Car Wash Chemical Cost Per Car Calculator — RevenueLab</a> (2026).</p>
Source: [Car Wash Chemical Cost Per Car Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/car-wash-chemical-cost-per-car) (2026).