Chemical purchases show what arrived and what was invoiced. They do not, by themselves, show what the wash consumed. Reconcile stock movements and the reporting period first, then compare measured application and inventory value on their own stated bases.
Open the inventory tool · Read the fictional case · Download the worksheets
Match stock counts, product state and dates
For each SKU, record opening and closing counts, delivery documents, supplier returns, transfers between locations and documented non-wash losses. Keep concentrate and ready-to-use quantities separate. The model accepts U.S. liquid gallons or liters for every quantity in one row. It does not convert weight to volume or infer a density from a product name. A container described as a gallon must be identified as U.S. or Imperial before it can be used.
Record how partly used containers were measured, who counted them and whether product remained in lines or dispensers at either count. A stock count taken before a delivery does not reconcile with a purchase report that includes that delivery unless the timing difference is recorded. An invoice credit can change value without changing physical quantity; a returned container can change both. Keep those two trails distinct.
Build the physical bridge before the per-wash ratio
Physical depletion equals opening quantity + receipts + transfers in − supplier returns − transfers out − closing quantity. Subtract documented non-wash loss to show the quantity attributed to washing. Compare that amount with an independently measured total application quantity for the same SKU, product state and period. Their difference remains unexplained until evidence resolves it.
The independent application measure must not simply be calculated from the same stock bridge. That would force an artificial match. Use a compatible independently observed meter, draw measurement or other qualified record, and document its accuracy and limitations. No expected dose is supplied by this tool. Use the installed equipment and product manufacturer’s instructions with the qualified service provider for operating decisions.
Fictional case: a stock difference is a question
| One fictional SKU | U.S. gallons |
|---|---|
| Opening quantity | 20 |
| Receipts | 40 |
| Closing quantity | 15 |
| Physical depletion | 45 |
| Documented non-wash loss | 3 |
| Wash-attributed depletion | 42 |
| Independent measured application | 39 |
| Unexplained difference | 3 |
The remaining three gallons could reflect a measurement, cutoff, transfer, product-state or operating issue. It does not establish leakage, employee conduct or improper dosing. Review the evidence before assigning a cause. If the application measure is missing, the result is unknown rather than zero variance. A negative physical depletion or loss greater than depletion must be corrected before results are produced.
Preserve the separate inventory-value bridge
Value consumed equals opening inventory value + net purchases + net transfer value − closing inventory value. Use a consistent adviser-reviewed valuation basis; do not multiply all stock by the newest supplier price. Price changes, freight, credits and the valuation method can make the dollar bridge differ from a simple quantity-times-price calculation.
In the fictional dollar case, $2,500 opening value + $4,000 net purchases − $2,000 closing value equals $4,500 consumed. Dividing by 3,000 matched completed washes gives $1.50 per wash. Purchases alone divided by the same count would show $1.33. This consumed-value ratio includes documented losses within the chosen stock population. Allocating a separate loss expense needs a supported value allocation, not an assumption based only on physical gallons.
Zero washes leaves a per-wash result undefined while preserving valid stock totals. Premium applications are not necessarily every completed vehicle: record a matched package count when relevant and inspect the POS definition. The tool rejects application counts above the selected completed-wash population; a different population needs a separately scoped review. Do not add unlike SKU volumes into a supposedly meaningful total chemical dose.
Read supplier and equipment terms
| Record | Question to resolve |
|---|---|
| Price and freight schedule | Which effective dates, minimum orders, credits or escalation terms apply? |
| Supply agreement | Are there exclusivity, termination or ownership-change provisions? |
| Dispensing equipment | Who owns it, supports it and approves changes? |
| Stock and application evidence | Are counts, units, states and periods compatible? |
| Product documentation | Are current labels, SDS and qualified training available for the actual products? |
NIST’s conversion table gives the rounded factor 3.785412 liters per U.S. gallon, used consistently here. OSHA’s hazard communication standard addresses chemical hazard information, labels, SDS and training. This financial worksheet does not prescribe mixing, dilution, protective equipment, storage or disposal methods.
Carry supported costs into the next analysis
Download the fictional case v1
Retain the source and follow-up reference for each SKU. Review utility bill reconciliation for fresh-water evidence and equipment diligence for support and condition questions. Carry supported costs into membership contribution or retail package economics once, with the population and period preserved.
Sources and scope
Official and original sources checked October 17, 2026. These sources support the identified rules and methods; they do not verify a particular business or property.
- NIST — NIST · SP 811 unit conversion tableSeparates U.S. and Imperial gallons and fluid ounces from mass ounces. Table gives 1 U.S. gallon = 3.785412 L, rounded. Use this documented factor consistently with a disclosed rounding tolerance. No mass-to-volume conversion or dilution inference.
- OSHA — OSHA · Hazard Communication, 29 CFR 1910.1200Labels, SDS access and employee hazard information support a qualified operating review. Inventory mathematics is not safe-use instruction. Do not prescribe mixing, dilution, PPE or disposal from a financial worksheet.
Continue your review
Verify the revenue · Normalize earnings · Model the cash flow