How to Calculate Your Utilization Rate (and What Yours Should Be)
SPI Research put average billable utilization across professional services firms at 66.4% in 2025, the lowest reading in the history of its Professional Services Maturity Benchmark, and well under the 75% the same report treats as the mark of a high performer. Clio, measuring lawyers rather than consultants, found something starker: 38% of an eight-hour day, or three billable hours. Different professions, same question. How much of the time you spend working is time somebody pays you for?
The formula takes ten seconds to write down. The arguments all happen underneath it, in the denominator, and that's where most people quietly flatter themselves. Divide by the wrong set of hours and you get a comfortable 80% next to a bank balance that disagrees.
The utilization rate formula
Utilization rate = (billable hours ÷ total hours) × 100
You worked 43 hours last week. Clients are paying for 27 of them. That's 27 ÷ 43 × 100, or 63%. The other 16 hours were real work with a value of zero on any invoice: the proposal that didn't land, the bookkeeping, the call with a prospect who went quiet, the hour lost to your own website.
If the billable and non-billable split is new to you, our guide to billable versus non-billable hours sorts the categories out first. Everything below assumes you can already tell them apart. If you'd rather skip the arithmetic, our free utilization rate calculator does all three of the calculations in this article, including the income target further down.
The denominator problem
Here's where two honest people get two different answers from the same week. Total hours can mean the hours you actually worked, or the hours you were available to work. Both are used in the wild, and they answer different questions.
Take that same week. Against the 43 hours you really worked, you're at 63%. Against a nominal 40-hour week, 27 ÷ 40 is 67.5%. The second number is higher and you didn't bill a single extra minute for it. All you did was hide the three hours of overtime by leaving them out of the bottom of the fraction.
Utilization against hours worked tells you how efficiently your working time converts into income. It's the number that answers "am I spending too much of my week on unpaid work?" and it's the one most freelancers want.
Utilization against available hours (capacity utilization) tells you how full your book is. Agencies and consultancies favor it because it exposes bench time. If a consultant is contracted for 40 hours and billed 27, capacity utilization says 67.5% and the missing 13 hours are the business's problem, whether they were spent on internal projects or on nothing at all.
Neither one is wrong, but comparing one against the other is. When you read that firms average 66.4%, that's capacity utilization measured against consultants' available hours, so measuring your own week against hours worked and feeling good about the comparison is a mistake. Pick a definition, write it down next to the number, and use the same one every time you check.
Over a year the gap gets wide. Say you take five weeks off and lose another week to public holidays, so you work 46 weeks at a nominal 40 hours, which is 1,840 hours of working time. Bill 1,150 of them and you're at 62.5% of the hours you worked, but only about 55% of the 2,080 hours in a standard US work year. The 2,080 version is the one to use when you're pricing a year, because holidays don't stop costing money while you're on them.
What actually counts as billable
The top of the fraction is billable hours, meaning hours you can legitimately put on a client's invoice. Not hours you did invoice, and not hours the client eventually paid for. Those are separate numbers and they come later.
People undercount here more often than they overcount. Client email is billable if it's about the engagement. So is the call where you talk a client out of a bad idea, the travel your contract says is chargeable, and the time you spend reading the material they sent you. Writing the proposal that won the job is not billable, because you were selling. Neither is the rework you're absorbing because you got something wrong.
A 2026 Smallpdf survey of 397 freelancers found respondents still lose an average of 204 hours a year to admin and paperwork even with AI tools in the mix. That's roughly 11% of an 1,840-hour working year gone before anyone has written a proposal. Admin like that belongs in your denominator, honestly recorded, or your utilization rate is fiction.
How to calculate your utilization rate in five steps
1. Pick a period you can actually reconstruct
A single week is too noisy to mean much: one dead Tuesday and you're twenty points down. A month is the smallest period worth acting on, and a quarter is better for spotting a trend. Whatever you choose, it has to be a period you have real records for. Utilization calculated from memory tends to come out about ten points too high, because the hours you forget are almost always the unpaid ones.
2. Count every hour you worked
All of it. Client work, admin, invoicing, marketing, the training you did on a Sunday, the Monday morning you spent fighting a printer. If you're using available hours instead, use your contracted or intended week (40 hours, or whatever you sell) multiplied by the number of weeks, and leave your holidays out of it.
3. Count the hours a client is paying for
Add up the billable side only. If you work at more than one rate, keep the hours as hours here; utilization is a time measure, and mixing money into it turns it into something else. The money question comes back in step five.
4. Divide, and label the result
Billable hours divided by total hours, times 100. Then write next to it which denominator you used. Six months from now, "Q3: 61% (hours worked)" is a data point you can compare against. A bare "61%" is a number you'll have to recalculate to trust.
5. Turn it into an effective hourly rate
This is the step that makes utilization mean something. Multiply your headline rate by your utilization. At £50 an hour and 62.5% utilization, every hour you work earns £31.25, and that's the figure to hold up against a salary or a job offer. It's also why a rate rise and a utilization rise are worth the same to you, and one of them is usually much easier to arrange.
What a good utilization rate looks like
Worth saying before the numbers: the published benchmarks come from firms that employ consultants, carry a sales team and pay for bench time. Yours doesn't. They're useful for orientation and poor as targets.
SPI Research's 2026 benchmark report put average billable utilization at 66.4% for 2025, down from 68.9% the year before and the lowest in the survey's history. SPI treats 70% as the minimum healthy level and 75% as where the best-run firms sit. In its 2024 data, IT consulting averaged 71.0% and management consulting 67.4%, so the spread between disciplines is real. Clio's 2025 Legal Trends data reports a 38% utilization rate for law firms, which is three billable hours out of an eight-hour day, and that lower figure reflects how much of a small firm's day goes on running the firm.
For a solo freelancer, 60% to 70% of hours worked is a good band, and it matches what most people find when they measure themselves for the first time. Above 75% sustained, either you're subcontracting your admin or you're not doing enough business development, and the second one shows up as an empty pipeline about a quarter later. Below 50%, something is wrong, and it's usually either that too much of the work you do is going unbilled or that the clients are too small to be worth their own overhead.
100% is not the goal and never was. A freelancer with no unpaid hours has no proposals in flight, no learning, and no slack for the week a project overruns.
The target your income implies
The more useful direction to run the formula is backwards. Instead of measuring your utilization and wondering whether it's good, work out what it has to be.
Start with what the business needs to bring in this year, say £55,000 to cover your income and your costs. Divide by your rate: at £50 an hour that's 1,100 billable hours. Now divide by the hours you'll actually work, the 1,840 from earlier, and you get just under 60%. That's your target utilization, and it comes from your own numbers rather than an industry average.
Then check it against reality. If you're running at 55% and the plan needs 60%, you have three levers: bill more hours, waste fewer, or raise the rate so the required hours drop. Working out which one is available is a different problem from knowing you need one of them. The calculator shows the gap between where you are and where the goal sits, and our guide on setting your hourly rate runs the same arithmetic from the other end.
Utilization is only the first leak
Firms that take this seriously track three numbers, not one, because time leaks out at three separate points. Utilization is how much of your day is billable. Realization is how much of that billable work you actually invoice. Collection is how much of what you invoiced gets paid.
Clio's 2025 figures show what happens when they compound: an eight-hour day produces 3.0 billable hours, of which 2.6 hours' worth gets invoiced (an 88% realization rate), of which 2.4 hours' worth gets collected (93%). Two and a half hours of pay out of eight hours at the desk. The median law firm also had 93 days of revenue sitting in lockup, unbilled or unpaid.
Freelancers leak in the same places, just less formally. Realization drops when you round a 90-minute call down to an hour, write off the extra afternoon because you feel awkward mentioning it, or forget to add a Thursday to the invoice. Collection drops when invoices go out late and get chased later. If your utilization is respectable and your income isn't, realization is usually the culprit, and it's the one nobody measures.
How to move the number without working more
The tempting response to a low utilization rate is a longer week, which shifts the fraction in the wrong direction: you add hours to both halves and the percentage barely moves while you get tired. Better options, roughly in order of how quickly they pay off:
- Bill the hours you already work. Recovering four forgotten billable hours a month at £50 is £2,400 a year, and it costs you nothing but a better record.
- Batch the admin. Invoicing, bookkeeping and email answered in fixed blocks eat less of the week than the same tasks sprinkled through it, because you stop paying the switching cost every time.
- Charge for the work that sits in the grey area. Discovery calls, scoping, revision rounds beyond the agreed number. Either put them in the contract as billable or price them into the rate, but stop absorbing them silently.
- Take fewer, larger engagements. Every client carries a fixed overhead of onboarding, meetings and invoicing. Five small clients cost far more unpaid time than one big one at the same revenue.
- Raise the rate. The one lever that improves your income without touching your utilization at all.
Measuring it without a Friday ritual
None of this works if the underlying record is a Friday-afternoon reconstruction. Utilization is a ratio of two numbers you have to be honest about, and the half that gets rounded away is always the unpaid half, which is precisely the half that makes the ratio informative.
The lowest-effort accurate record is the one you're already keeping. Your calendar has Tuesday's client call, Wednesday's workshop and Thursday's internal planning session, with real start and end times attached. VibaCloud imports those events from Outlook or Google, turns them into a draft weekly timesheet, and lets you tag each one to a client and project and mark it billable or not. Because the non-billable lines stay on the sheet at zero value instead of being deleted, both halves of the fraction survive to the end of the week. The reports then give you the billable and non-billable split by week without you calculating anything, and it's free.
A spreadsheet does the same job if you keep it up. Our free weekly timesheet template has the billable column and the totals already in it. The tool matters less than the habit of recording the unpaid hours at all.
The bottom line
One number is worth writing on a sticky note: your rate multiplied by your utilization. That's what an hour of your working life is actually worth, and at 62.5% a £50 rate is really £31.25. Most people who calculate it for the first time go quiet for a moment, then either raise their rate or go looking for the unpaid hours. Both are the right response.
Frequently asked questions
What is the formula for utilization rate?
Billable hours divided by total hours, multiplied by 100. If you worked 43 hours last week and 27 were billable, your utilization rate is 63%. The only decision that changes the answer is whether total hours means the hours you worked or the hours you were available to work.
What is a good utilization rate?
For a solo freelancer, 60% to 70% of hours worked is a healthy band. SPI Research put the average for professional services firms at 66.4% in 2025 and treats 75% as high-performer territory, though those figures measure available hours rather than hours worked, so they aren't directly comparable to a freelancer's number.
Should I use hours worked or available hours as the denominator?
Use hours worked if you want to know how efficiently your time converts into income, which is the usual freelance question. Use available hours if you want to know how full your book is. Whichever you pick, record which one it was, because the two can differ by five points or more on the same week.
What's the difference between utilization and realization?
Utilization is the share of your time that is billable. Realization is the share of that billable work you actually invoice. Clio's 2025 data puts law firm realization at 88%, so roughly one hour in eight of genuinely billable work never reaches an invoice at all.
Is 100% utilization possible?
Briefly, and it's a warning sign. Every freelance business needs unpaid hours for proposals, invoicing, learning and the projects that overrun. A month at 100% usually means the business development stopped, and the empty pipeline arrives about a quarter later.
How does utilization affect my hourly rate?
Directly. Your effective earnings are your rate multiplied by your utilization, so £50 an hour at 62.5% utilization is really £31.25 for every hour you work. If you set a rate by dividing a target income by 2,080 hours, you've assumed 100% utilization and priced yourself below cost.
How often should I calculate it?
Monthly is enough to act on and quarterly is enough to see a trend. A single week swings too much to mean anything. What matters more than the frequency is that the underlying record includes your non-billable hours, because those are the ones that quietly vanish when you reconstruct a week from memory.
