Most used-car managers can tell you how many units are over 60 days old. Far fewer can tell you, to the euro, what those units are draining from the business every single day they sit. The cost of aged car stock is not a vague worry about a tired-looking forecourt. It is a specific, calculable number made up of depreciation, floorplan interest and the opportunity cost of cash you can no longer deploy. When you put a daily figure on it, the conversation about a slow car changes completely.
This guide is a definitional, calculator-style explainer. It breaks the total holding cost of a single unit into its three components, shows you how to combine them into a daily holding cost per car, and explains how to read that number against the margin still left in the deal. It is deliberately not a clearance playbook and not a portfolio metric, it is the underlying arithmetic that makes both of those decisions defensible.
Why "days in stock" is only half the story
Age is a proxy, not the cost itself. Two cars at 75 days can have wildly different holding costs. A small city runabout in a stable segment bleeds slowly. A high-value executive saloon facing a model-year change or an EV price reset can lose more in a fortnight than the small car loses in a quarter.
That is why a single ageing report, however red it looks, does not tell you what to do. It tells you which cars are old. It does not tell you which old cars are expensive to keep. The job of a dead-stock cost calculation is to convert age into money, per unit, per day, so that the worst offenders rise to the top regardless of how the rest of the report is sorted.
The three components of holding cost
1. Depreciation: the silent, largest cost
Depreciation is the market value the car loses while you own it. It is the component most dealers under-count, because nothing leaves the bank account when it happens. The car is simply worth less than it was last month, and you only feel it at the point of sale.
Depreciation is not uniform. It depends on segment, fuel type, season and model-year timing. EVs and plug-in hybrids have shown that residual values can move sharply when the new-car price ladder or incentive landscape shifts, which is one reason electrification is reshaping residual values and EV pricing faster than older rules of thumb assume.
To estimate it, take a realistic monthly depreciation rate for the segment and apply it to current market value:
- A EUR 30,000 car depreciating at an illustrative 1.5 percent per month loses roughly EUR 450 that month, or about EUR 15 per day.
- The same rate on a EUR 8,000 car is about EUR 120 per month, or EUR 4 per day.
The point is not the exact percentage. It is that depreciation scales with the value at risk, and on a higher-value unit it usually dwarfs every other line.
2. Floorplan interest: the cost you can see
Floorplan (stocking) interest is the financing charge on the capital used to buy the car, whether that is a dedicated stocking facility or your own working capital priced at its borrowing rate. Unlike depreciation, this one shows up on a statement, which is why it is the component most managers already track.
The daily floorplan cost is straightforward:
daily floorplan = (amount financed x annual rate) / 365On a EUR 20,000 car financed at an illustrative 9 percent annual rate, that is roughly EUR 4.93 per day. Over a 90-day hold, around EUR 444. Useful to know, but on its own it badly understates the true cost, because it ignores both depreciation and what that capital could have earned elsewhere.
3. Opportunity cost: the deal you didn't do
The third component is the hardest to feel and the easiest to ignore. Every euro locked in an aged unit is a euro not working in a car that would turn in 30 days. That is opportunity cost: the return your capital would have generated had it been recycled into faster-moving stock.
If your funded equity in a car would otherwise earn a gross margin by being turned two or three times a year, the foregone margin is real, even though no invoice records it. A conservative way to approximate it is to apply your internal cost of capital, or, more aggressively, your typical per-unit gross divided by your average days-to-sell, to the equity tied up in the unit. The longer the car sits, the more turns you have forfeited.
Putting it together: the daily holding cost per unit
Add the three components and you have a single, decision-ready number.
| Component | What it measures | Illustrative driver | Daily figure (EUR 25,000 car) |
|---|---|---|---|
| Depreciation | Market value lost while owned | ~1.3% of value per month | ~10.80 |
| Floorplan interest | Financing cost on capital | ~9% annual on amount financed | ~6.16 |
| Opportunity cost | Return foregone on tied-up cash | Internal cost of capital on equity | ~3.00 |
| Total daily holding cost | True cost to keep the unit one more day | ~19.96 |
On this illustrative EUR 25,000 unit, keeping the car one more day costs roughly EUR 20 in total, close to EUR 600 a month, of which depreciation and opportunity cost together make up the majority and neither appears as a line item anywhere. That is the number that should sit next to every aged unit, not just its age in days.
How to use the number once you have it
A daily holding cost is only useful if it changes a decision. Three practical uses:
- Set a stop-loss per unit. Compare the remaining margin in the car against its accumulating holding cost. When another month of holding would cost more than the margin you are defending, the car has crossed from "patient" to "bleeding". This is the honest trigger behind any decision to clear aged used-car stock rather than wait.
- Prioritise repricing. The highest daily-cost units are where a price move pays back fastest. A EUR 500 price drop that brings a forward sale on a EUR 20-a-day car can be cheaper than two more weeks of holding. This is the core logic of disciplined repricing of used-car stock.
- Feed the portfolio view. Per-unit daily cost rolls up into a stock-wide picture of how much margin is exposed to time. That aggregate is what the margin-at-risk inventory metric is built to express across the whole forecourt.
The single biggest lever, of course, is not holding the cost down, it is not incurring it in the first place. Everything that helps you reduce days in stock, from sharper buying to faster reconditioning, compounds directly against this daily figure.
Common mistakes that hide the real cost
- Counting only floorplan. It is the visible cost, so it becomes the whole story. On most units it is the smallest of the three components.
- Using purchase price instead of current market value for depreciation. Depreciation runs on what the car is worth today, not what you paid. As value falls, the euro-per-day figure changes, usually it slows, which is its own signal.
- Ignoring reconditioning that is still unrecovered. Money spent preparing the car is part of what the unit owes you. It raises the equity at risk and therefore the opportunity cost.
- Treating all aged stock as equally urgent. A cheap, stable car at 90 days may cost less per day than an expensive, volatile car at 45. Days alone will mislead you; cost per day will not.
Where VehIQ fits
A dead-stock cost calculation is only as good as the inputs behind it, a realistic current value, a segment-aware depreciation rate, and a clear view of what each unit owes you. Those inputs are exactly where most dealers are working blind, relying on a single book figure with no sense of how confident it is.
VehIQ is being built as the data and intelligence layer that makes this kind of calculation routine rather than a spreadsheet exercise. It is designed to provide AI valuations that show their sources and a confidence interval instead of one black-box number, drawn from canonical European vehicle data with field-level lineage, and to surface inventory signals such as days-to-sell and margin-at-risk alongside the stock you already manage. It is designed to run beside your existing systems rather than replace them, on EU-sovereign infrastructure with data in open formats you own. VehIQ is pre-seed and early in its build; the aim is to give the daily holding-cost number a foundation you can trust, so the decision to hold, reprice or trade out is made on evidence rather than instinct.