How is time utilisation calculated?
The American Rental Association defines time utilisation as a dimensionless value that quantifies the fraction of the fleet on rent for a given period. The formula is: Days Rented divided by Total Days Available, multiplied by 100.
If you have ten pieces of equipment and each is available for 30 days in a month, your total available days are 300. If those ten pieces were collectively on rent for 210 of those days, your time utilisation is 70 percent.
The ARA standardised this definition in its 2011 publication, ARA Rental Market Metrics, specifically so that operators could compare their numbers against other companies on a consistent basis.
For most general rental fleets, a time utilisation of 65 to 75 percent is the target range. Below 60 percent is a signal that you are carrying more equipment than your market can absorb. Consistently above 80 percent is a signal that customers are being turned away and demand is going unmet.
How is dollar utilisation calculated?
The ARA defines dollar utilisation as a dimensionless measure of annualised revenue that quantifies the fraction of fleet OEC value that is on rent for a given period. The formula is: Annual Rental Revenue divided by Original Equipment Cost.
OEC is what you paid for the equipment new, sometimes called the original equipment cost or book cost. The revenue figure used in this calculation excludes damage waiver fees, delivery charges, environmental fees, and re-rents, per Rental Equipment Register fleet management guidance. Including those items would inflate the number and make comparisons meaningless.
If your fleet cost $500,000 to acquire and you generated $275,000 in qualifying rental revenue over the year, your dollar utilisation is 55 percent.
Why can the two metrics point in opposite directions?
This is the most important thing to understand about using both metrics together.
A machine can show high time utilisation and low dollar utilisation at the same time. If a $500 power drill is on rent every day but a $75,000 skid steer sits idle, your physical time utilisation might be 50 percent while your dollar utilisation is only 1 to 2 percent. The drill is working hard. The skid steer is costing you money every day it sits.
Time utilisation treats every unit equally regardless of what it cost. Dollar utilisation weights each unit by its acquisition cost, so expensive idle equipment shows up as a real drag on the number. That is why a fleet manager who only watches time utilisation can feel satisfied with a busy yard while the most capital-intensive assets are underperforming.
The reverse is also possible. A fleet of heavy earthmoving equipment might show modest time utilisation because those machines rent for long periods at high day rates. Dollar utilisation can look healthy even when the equipment is not moving every week.
What are realistic targets for each metric?
Targets depend heavily on fleet type, not just company size. The numbers below apply to general rental fleets and national equipment rental chains. Party and event rental operates under entirely different economics and is addressed separately.
For time utilisation in general rental, the target is 65 to 75 percent. Below 60 percent suggests excess inventory. Consistently above 80 percent suggests demand is going unmet.
For dollar utilisation, national equipment rental chains typically operate in the 55 to 65 percent range. Independent operators tend to run lower. Published data from Rental Equipment Register shows that independent rental operations average 38.1 percent dollar utilisation with a median fleet age of 36.2 months. That gap between independents and national chains is real and worth knowing when you set your own targets.
Party and event rental companies are a different case entirely. Because their inventory turns over quickly at high rates relative to low acquisition costs, dollar utilisation rates of 150 percent or higher are possible in that segment. Applying general rental benchmarks to a party rental operation, or vice versa, will produce misleading conclusions.
Fleet composition also matters within general rental. The higher the per-unit acquisition cost, the lower the dollar utilisation percentage you can typically expect. A fleet built around heavy earthmoving equipment will naturally produce lower dollar utilisation than a fleet of small tools and compaction equipment, even if both fleets are managed well. Set your targets based on what you actually own.
Does it matter which metric I focus on?
Neither metric is sufficient on its own. Time utilisation is easier to track day to day and is useful for scheduling maintenance, spotting underused units, and making buy or sell decisions on individual pieces. Dollar utilisation is the number that connects fleet activity to financial performance. It tells you whether the capital you have tied up in equipment is earning a return.
A common mistake is to optimise time utilisation without watching dollar utilisation. You end up with a busy fleet that is not profitable because the high-cost units are sitting while the low-cost units run. The opposite mistake is to focus only on dollar utilisation without tracking time utilisation by unit, which means you miss the individual machines that are dragging the average down.
Some operators use rental management software to track both metrics by unit, by category, and across the whole fleet, rather than pulling numbers from separate spreadsheets. Whatever system you use, the goal is to see both numbers together, not in isolation.
What should an operator actually do?
- Calculate your current time utilisation using the ARA formula: Days Rented divided by Total Days Available, multiplied by 100. Do this for the whole fleet and then by equipment category.
- Calculate your dollar utilisation using Annual Rental Revenue divided by OEC. Strip out damage waiver, delivery, and environmental fees before you run the number, per ARA and Rental Equipment Register guidance.
- Compare your time utilisation against the 65 to 75 percent target range for general rental. Flag any category below 60 percent as a candidate for disposal or reduced reinvestment.
- Compare your dollar utilisation against the 38 percent independent average and the 55 to 65 percent national chain range. Adjust your target based on your fleet composition, particularly if you carry heavy equipment with high OEC.
- Look for units with high time utilisation and low dollar contribution. Those are the pieces keeping your dollar utilisation down.
- Review both metrics regularly. The ARA defines dollar utilisation on an annualised basis, so at minimum run the full calculation once a year. Track time utilisation more frequently so you can act on individual units before idle periods extend.