Index
What are days of stock and why do they matter more than sales volume
How it is calculated: the formula and a step-by-step example
What is a reasonable threshold by segment
How to interpret the indicator by vehicle type
What to do when days of stock increase
Days of stock and real financing cost: the calculation many overlook
Dealcar and real-time days of stock control
Frequently asked questions
What are days of stock and why do they matter more than sales volume
Days of stock measure the average time a vehicle remains in the dealership's inventory from the moment it enters until the sale is signed. It is an efficiency indicator: the lower it is, the faster capital rotates and the less cost each vehicle accumulates.
A dealership can sell 30 cars a month and have a business with financial problems if those cars take an average of 90 days to leave. Another that sells 15 cars a month but with a turnover of 25 days can have more liquidity and more net margin. Sales volume does not tell the whole story. Days of stock do.
The metric connects directly with three critical business variables: the inventory financing cost (if you have stock finance, every day has a cost), market depreciation (a car that does not rotate can lose value while stationary) and the ability to reinvest capital in new purchases.
Read the full breakdown of the real cost of a car sitting in stock.
How it is calculated: the formula and a step-by-step example
There are two ways to calculate it, depending on whether you want the data for a specific vehicle or the dealership average.
For a specific vehicle: Days in stock = Date of sale (or today's date if still unsold) minus the date of entry into inventory.
A Golf that entered on 1 April and was sold on 28 April has been in stock for 27 days.
For the dealership average (monthly period):
Average days of stock = Sum of days in stock of all vehicles sold in the period / Number of vehicles sold in that period.
Specific example: in May you sold 12 cars. The days in stock for each were: 18, 34, 22, 45, 12, 67, 29, 41, 15, 38, 53, 24. Total sum: 398 days. Average: 398 / 12 = 33 days.
This means that, on average, each car sold in May was in your inventory for 33 days before leaving. It is a useful number to compare with previous months and with the threshold you have set for yourself.
Read what KPIs a dealership should measure to control its business.
You can also calculate the days of stock of live inventory, that is, of cars that have not yet been sold. In that case, the reference date is today, not the sale date. That number tells you how many days each car has been stationary at this moment and which ones need urgent attention.
What is a reasonable threshold by segment
There is no single valid number for all dealerships. The reasonable threshold varies depending on the price segment and the type of vehicle.
Segment | Reasonable days of stock | Alert signal |
|---|---|---|
Budget cars up to £5,000 | Less than 20 days | More than 35 days |
Saloons and SUVs £5,000-£15,000 | 20-40 days | More than 55 days |
Premium vehicles £15,000-£30,000 | 30-60 days | More than 75 days |
Luxury vehicles over £30,000 | 45-90 days | More than 120 days |
Used electric vehicles | 25-50 days | More than 70 days |
These ranges assume reasonable publishing operations and pricing adjusted to the market. A car that enters stock on a Monday and is not published until the following Thursday is already 3 days late without generating any contact.
The threshold you should set as a dealership is the one that makes the operation profitable. If you have stock finance at 7% per annum and an average net margin of £1,600 per car, the maximum financing cost per vehicle that you can absorb without destroying the margin gives you your personalised days of stock threshold.
Value any vehicle, calculate the margin, and compare with real-time market data using Dealcar's valuator and market radar. More information at dealcar.io/tasacion.
How to interpret the indicator by vehicle type
Days of stock are not interpreted the same way for all vehicles in the inventory. A distinction must be made between what is normal for that type of car and what is a warning sign of a problem.
An economical budget car that has been unsold for 40 days is a clear sign: either the price is high or there is a presentation problem. This type of car sells quickly if the price is right. If it has not sold in 40 days, something is wrong.
A premium SUV worth £22,000 that has been in stock for 45 days may be within the norm: the buyer in that segment takes longer to decide, compares more options and sometimes needs to arrange financing before committing.
A luxury vehicle worth £45,000 that has been in stock for 90 days may be perfectly normal or it could be a sign that the price is out of step with the market. In that segment, the difference between a correct price and one that is 5% high can mean weeks of difference in turnover.
That is why days of stock analysis must always be done in context: comparing with the history of the same type of vehicle in your dealership, rather than applying a single metric to the entire inventory.
See also how Euro 7 regulations and LEZs affect used stock.
What to do when days of stock increase
When the average days of stock for the month exceeds your usual threshold, there are four levers of action sorted by cost and speed of impact.
Price adjustment. This is the most direct lever. A car that has been unsold for 45 days and is at market price probably needs a drop of between 3% and 7% to start generating enquiries again. A car at £12,000 that drops to £11,500 can go from no enquiries to several interested buyers in a few days.
Check how to reduce days in stock with dynamic pricing.
Greater visibility on portals. Feature the advert, renew the photos or expand the description. Many portals prioritises in the results the most recent adverts or those that have more interactions. An advert that has been published for 40 days without being touched has lost visibility compared to new adverts.
Channel change. If the car has been published on the same portals for weeks without response, it may have more reach in a different channel. A niche vehicle (sports car, 4x4, van) may have more demand in specialized portals or on Facebook groups than on generalist portals.
Review of the buying target. If several cars of the same type have been sitting idle for a while, the problem may not be the sale but the purchase. You may have bought a vehicle profile that does not turn over well in your area or in your usual price range. This analysis prevents repeating the same mistake in the next purchase.
Days of stock and real financing cost: the calculation many overlook
If you have a stock finance line, every day that a car is in inventory has a direct cost that accumulates silently and that many dealerships do not include in the calculation of the real margin of each operation.
Read also what stock finance is and how it works for dealerships.
The calculation is simple. If the purchase value of the vehicle is £10,000 and your interest rate of the stock finance is 7% per annum, the daily financing cost is: 10,000 x 0.07 / 365 = £1.92 a day.
If that car takes 80 days to sell, the accumulated financing cost is £153. If it takes 30 days, it is £57. The difference of 50 days means £96 less net margin on that operation.
At scale, with 20 cars in stock with an average value of £10,000 and a difference of 20 days in the average turnover, the difference in financing costs is approximately £767 per month. That money does not appear explicitly on any invoice, but it comes out of the margin of each vehicle.
That is why reducing days of stock is not just a matter of operational efficiency: it is a direct lever on business profitability.
Dealcar and real-time days of stock control
Dealcar automatically records the entry date into stock of each vehicle and calculates in real time the days it has been in inventory. From the dashboard you can see at a glance which cars are above your usual threshold and act before the capital lock-up cost eats into the margin.
The system also allows you to calculate the average days in stock by period, by type of vehicle and by sales channel, which facilitates the analysis of what is working and what is not in your turnover operations. If you want to see how it works, request a demo at dealcar.io.
Frequently asked questions
Are days of stock counted from when I buy the car or from when I publish it?
From when the car enters your inventory, which usually coincides with the purchase or collection date of the vehicle. Publishing it later does not "stop the clock": financing cost and depreciation start from when the vehicle is yours. That is why preparing and publishing the car as soon as possible is part of turnover management.
Does it make sense to calculate the days of stock of cars that have not yet been sold?
Yes, and it is especially useful. Knowing that you have 4 cars that have been in stock for more than 60 days gives you actionable information: you can act on those specific vehicles before the problem worsens. Do not wait for the end of the month to review turnover: do it weekly with the live inventory.
How do days of stock affect the calculation of the real margin?
The gross margin (selling price minus purchase price) does not include the cost of days of stock. The net margin must include it: selling price minus purchase price minus preparation minus administrative costs minus financing cost proportional to the days in stock. A car with a £2,000 gross margin and 90 days in stock with 7% financing has a real net margin that is between £300 and £500 lower, depending on the purchase value.
What happens if a car has been in stock for more than 90 days and there is no buyer?
Beyond a certain point, the price must be lowered enough to move it on, even with a minimal margin. A car that has been in stock for 120 days is generating costs every day and occupying space that could hold a vehicle with faster turnover. Keeping it in the hope of finding the buyer at the original price is usually a mistake: the opportunity cost of that tied-up capital usually exceeds the difference in price that you hope to recover.
Do days of stock affect the valuation of the dealership if I want to sell it?
Yes. A buyer or investor analyzing a dealership looks at average stock turnover as an indicator of operational efficiency. A high and constant turnover is a sign of a well-managed business. Stock with many cars over 60 days indicates buying or selling issues that the buyer will have to resolve.
