Quick answer
The right fleet size is the number of vehicles that covers your normal workload with a small buffer for peaks and breakdowns, without vehicles sitting idle. Measure how many vehicle-days your work needs each week, compare it with what your current fleet provides, and add a vehicle only when the work it unlocks — or the hire costs it avoids — clearly exceeds what it costs to own.
Key points
- Measure demand in vehicle-days per week, not just headcount.
- Track utilisation: an idle vehicle still costs finance, insurance and registration.
- Plan a buffer for breakdowns and peaks — but price it honestly.
- Short-term hire can be cheaper than owning a vehicle for rare peaks.
- Add a vehicle when the work it unlocks clearly exceeds its total cost.
Every growing business with vehicles hits the same question sooner or later: do we need another one? Get it wrong one way and you’re turning down work, paying for hire vehicles and running staff ragged. Get it wrong the other way and you’ve got a ute sitting in the yard costing money every day.
Fleet sizing doesn’t need to be guesswork. With a few weeks of simple records, you can work out the right number — and know exactly when the next vehicle will pay for itself.
Why fleet size matters
Every vehicle carries fixed costs whether it moves or not: finance repayments, insurance, registration and depreciation. On top of that come running costs when it’s used. A vehicle that’s used every working day spreads those fixed costs across a lot of productive work. A vehicle used one day a week carries the same fixed costs with a fraction of the benefit.
Too few vehicles has costs too, just less visible ones:
- jobs declined or delayed
- staff waiting for a vehicle, or doubling up
- hire vehicles at short notice, often at peak prices
- no backup when a vehicle breaks down
- more kilometres and wear on the vehicles you do have
Step 1: measure demand in vehicle-days
Headcount is a starting point, but it’s not the right measure. Some staff need a vehicle every day; others share; some jobs need two vehicles. Instead, count vehicle-days: for each working day over a few typical weeks, how many vehicles did your work actually need?
Keep it simple — a whiteboard or spreadsheet with dates down the side and a tally of vehicles needed each day. Include days when you hired a vehicle, borrowed one, or turned work away for lack of one. Those are the days that tell you the most.
Step 2: measure utilisation
Utilisation is the share of available working days each vehicle is actually used. Track it for each vehicle over the same weeks.
| Utilisation pattern | What it usually means |
|---|---|
| Most vehicles used nearly every day | Fleet is fully used — little buffer for breakdowns or peaks |
| One vehicle rarely used | Possible surplus — could it be sold or reassigned? |
| All vehicles busy plus frequent hires | Likely under-sized — another vehicle may pay for itself |
| Busy in some seasons, idle in others | Consider hiring for peaks rather than owning |
Step 3: decide how much buffer you need
A fleet with no spare capacity has no answer to a breakdown. How much buffer you need depends on what downtime costs you:
- High cost of downtime — refrigerated deliveries, contract routes with penalties, emergency trades. A spare vehicle, or a guaranteed hire arrangement, may be worth it.
- Moderate cost — trades and services where jobs can usually be rescheduled. A hire arrangement for emergencies may be enough.
- Low cost — work that can flex easily. Little or no buffer needed.
Price the buffer honestly. A spare vehicle has the same fixed costs as any other. Compare that with what you’d spend on hire and lost work in a typical year.
Step 4: own, hire or subcontract for peaks?
Not every peak needs another owned vehicle. For short, predictable peaks — a seasonal rush, a single big job — short-term hire or subcontracting may be cheaper. For sustained growth, owning usually wins, because the fixed costs are spread across lots of work.
A useful rule of thumb: if you find yourself hiring the same kind of vehicle repeatedly, add up what you spent on hire over the last year and compare it with the yearly cost of owning one. When hire costs approach ownership costs, it’s time to buy.
Step 5: know when the next vehicle pays for itself
The case for another vehicle is strongest when you can point to the work it will unlock or the costs it will remove:
- Work currently declined — what’s it worth in gross profit each month?
- Hire costs avoided — what did you spend last year?
- Overtime or travel saved — fewer staff waiting or doubling up
- A contract won — new routes, a maintenance contract, a new site
Compare that with the vehicle’s total monthly cost — repayment, insurance, registration, fuel, servicing and depreciation. Our guide to fleet total cost of ownership shows how to build the full figure, and the fleet cost planner works out the amount to finance across several vehicles.
When the benefit comfortably exceeds the cost, the next vehicle is earning its keep. If you’d like to test the finance side, a quick enquiry gets a specialist’s view without a credit check.
A worked example (illustrative)
A cleaning business runs four vans. Over six weeks, the owner records daily demand and finds that on most days all four vans are in use, and on roughly one day a week a fifth job is either declined or covered by hiring a van. Hire costs have been creeping up, and two regular clients have asked about extra services that would need another van most days.
Adding up the declined work, the hire spending and the new services, the owner estimates the fifth van would be busy most working days. Its total monthly cost is well below the gross profit it would unlock. The owner finances a fifth van and, because the original four were bought together, chooses a slightly different term so the replacement dates start to stagger.
Your numbers will differ. The method — measure, compare, then decide — is what matters.
Don’t forget drivers and parking
A vehicle needs a licensed driver and somewhere to park it securely overnight. Before adding vehicles, check you have the people to drive them and the space to keep them. For larger vans and trucks, check licence classes: Transport for NSW, for example, says a car licence covers vehicles up to 4.5 tonnes gross vehicle mass.
Growing in stages
If the numbers point to several more vehicles, consider adding them in stages rather than all at once. You’ll learn from the first addition before committing to the next, cash flow stays steadier, and replacement dates naturally spread out. See multiple vehicle finance and vehicles for a new contract for how lenders approach fleet growth.
When to sell a vehicle instead
Fleet sizing works both ways. If your records show a vehicle sitting idle most days, selling it may free up cash and cut fixed costs. Before you do, check whether it’s your only buffer for breakdowns or peaks, and what it would cost to hire when you need one. If a vehicle is under-used because it’s the wrong type — a van when you need a ute, or vice versa — swapping it may solve two problems at once. Our guide on choosing between a ute and a van helps with that decision.
Telematics and simple tracking
Many businesses now use GPS tracking or telematics to see how often each vehicle is used, where it goes and how it’s driven. You don’t need it to size a fleet — a whiteboard works — but once you have several vehicles it makes utilisation easy to measure and can highlight vehicles that are under-used or driven hard. It also helps with logbooks: the ATO explains that a logbook recording business and private travel supports the business-use percentage you claim.
Ready to add the next vehicle?
If your records say another vehicle will pay its way, let’s get the finance sorted. It takes about 60 seconds to enquire, and asking won’t leave a mark on your credit file. We don’t pass your details around a crowd of lenders; one specialist handles it and calls you personally. Please give us accurate details on the form — the vehicle, the price and how it fits your workload — so we can match you with the right lender first go.
Frequently asked questions
How do I know if I need another vehicle?
Signs include regularly turning down work, staff waiting for vehicles, frequent hire costs and long travel times because one vehicle is doing too many jobs. Measure demand in vehicle-days and compare it with your fleet's capacity.
What is vehicle utilisation?
It's the share of available working days a vehicle is actually used. Low utilisation means a vehicle may not be earning its keep; very high utilisation leaves no room for breakdowns.
Should I keep a spare vehicle?
It depends on what downtime costs you. If a vehicle off the road means lost jobs or a spoiled load, a spare — or a reliable hire arrangement — can pay for itself. If not, hiring when needed is often cheaper.
Is it better to hire vehicles for peak periods?
For short, predictable peaks, hiring is often cheaper than owning a vehicle that sits idle for most of the year. For sustained growth, owning usually wins.
Can I finance one vehicle now and more later?
Yes. Many businesses add vehicles in stages as work grows, which also helps stagger replacement dates.