The three numbers
| Number | Formula | What it answers |
|---|---|---|
| Utilisation | rented days ÷ available days | Is this unit busy enough to justify its space? |
| Revenue per unit | total revenue in period ÷ 1 unit | Does it earn more than it costs to own? |
| Average rental length | rented days ÷ number of rentals | How much handling work per earned day? |
You can add margin, cost per rental and repeat-customer rate later. Start with three; a metric you compute every month beats five you compute once.
Utilisation, defined properly
Utilisation looks trivial until you try to calculate it, at which point every ambiguity in your data surfaces at once.
Rented days are days the unit was out on a paid rental. Count part days consistently — either every started day counts as one, or you count charged days. Either works; mixing them does not.
Available days are the days the unit could have been rented. The choice that matters is what to do with downtime:
- Calendar utilisation — available days = every day in the period, including days off the road. Shows the return on your capital.
- Operational utilisation — available days exclude maintenance, repairs and statutory inspections. Shows how good you are at selling the capacity you actually had.
Both are legitimate. Track calendar utilisation as your headline number, because that is the one that reflects money spent, and keep the operational figure alongside it — the gap between the two *is* your downtime cost, expressed in days.
A worked example. A trailer in a 30-day month is out on rental for 12 days and off the road for repair for 5.
- Calendar utilisation: 12 ÷ 30 = 40 %
- Operational utilisation: 12 ÷ 25 = 48 %
- Downtime cost: 8 percentage points, or roughly two lost rentals at your average length.
What a "good" number looks like
There is no universal target, and anyone quoting one without a season and a unit type is guessing. The useful frame is relative:
| Situation | Typical reading | What to do |
|---|---|---|
| Under 20 % in season | too many units, wrong unit, or nobody knows you have it | check visibility first, price second, then consider selling |
| 25–45 % in season | normal for general trailer and tool hire | fine; look at rental length instead |
| Over 60 % in season | you are turning work away | raise the price or add a unit — probably both |
| Over 80 % sustained | definitely underpriced | raise the price before you buy; the extra margin funds the purchase |
| Under 10 % out of season | normal for seasonal kit | manage with off-season pricing, not panic |
The asymmetry is deliberate: high utilisation is a pricing signal long before it is a buying signal. Raising rates on a unit that is out 80 % of the time costs you a few rentals you did not have capacity for anyway, and it pays for the next one. See Seasonal Pricing for a Rental Fleet for handling the peak and trough separately.
Revenue per unit, and the number under it
Revenue per unit tells you which units earn. Cost per unit tells you which ones keep it. Both matter, and you already know most of the inputs:
- Ownership: purchase price spread over expected life, or lease payments.
- Fixed running costs: insurance, road tax where applicable, statutory inspections, storage space.
- Variable costs: servicing, tyres, consumables, repairs after damage.
- Handling: the staff time each rental takes — the number people always forget, and the one that makes short rentals expensive.
Divide annual cost by the number of days the unit was actually rented last year, not by 365. That gives you the break-even day rate, and it is nearly always higher than owners expect, because the denominator is 100–150 days rather than 300. The pricing consequences are set out in How to Price Equipment Rentals.
Average rental length: the quiet lever
Handling cost is per rental, not per day. Two three-day rentals and one six-day rental produce the same rented days and very different amounts of work: two handovers, two returns, two cleans, two sets of paperwork versus one of each.
That is why extending average rental length is usually the cheapest growth available to a small fleet. Practical moves:
- Tapered rates so day four is cheaper than day one. Without a taper, weekly hire simply does not happen.
- A weekend rate priced as a unit rather than as two days.
- A weekly price you advertise, not one you only mention when asked.
- A sensible minimum for units that are expensive to turn around, so a two-hour hire does not consume an afternoon.
Track it monthly. If average length is falling while utilisation stays flat, your workload is rising for the same money.
Collecting the data without a system
You do not need software to start. You need a clean row per rental with five fields: unit, start date, end date, revenue, and a note of any days the unit was off the road.
From that you can produce, per unit and per month:
- rented days (sum of durations),
- available days (days in month, minus downtime for the operational figure),
- revenue,
- number of rentals.
Two pivot tables and you have all three numbers. The realistic warning is that this is only as good as the underlying rows — if bookings are recorded as text, or changed dates were never updated, the analysis inherits the mess. Running a Rental Business on a Spreadsheet covers how to keep those rows clean enough to be worth analysing.
A monthly review that takes fifteen minutes
Do this on the same day each month. It is short on purpose — a review you actually perform beats a dashboard you admire.
1. Utilisation per unit for the month, sorted ascending. Look at the bottom two and the top two only.
2. Revenue per unit, same period last year if you have it. Absolute numbers matter less than direction.
3. Average rental length for the fleet, and separately for your busiest category.
4. Downtime days and why. Three repairs on the same unit is a replacement conversation.
5. One decision. Price change, purchase, sale, or a marketing push for a specific unit. One per month, executed, beats five noted.
Keep the answers in one sheet, one row per month. After a year that sheet is the most valuable document in the business — it is the only thing that shows you seasonality in your own numbers rather than in general advice.
What the numbers do not tell you
Three honest caveats, because metrics used naively cause bad decisions:
- A low-utilisation unit can still be strategically right if it wins whole jobs. The tipping trailer that goes out six times a year may be why a builder rents everything else from you.
- Utilisation ignores wear. Two units at 50 % can have very different remaining lives depending on who used them and how.
- Revenue is not margin. The unit with the highest revenue may also be the one with the highest damage rate. If your damage costs are material, track them per unit as well — Wear and Tear vs. Damage covers how to separate normal wear from chargeable damage in the first place.
Where Flotello fits
Flotello records every booking, block and payment against a specific unit, so utilisation, revenue per unit and average rental length come out of data you were entering anyway rather than out of a monthly reconstruction. The point is not the chart — it is that the number is available in the week when the decision is being made. There is a seven-day trial without a card.