What Are Billable Hours? The Complete Guide (2026)

Billable hours are the hours of work you can charge a client for, usually logged in fixed increments and multiplied by an hourly rate. Harvest and Clockify (invoicing on Standard and above) cover tracking through invoicing. Toggl suits teams that need billable rates and profitability reports. Timing and Memtime capture time automatically on the Mac, so less of your week has to be rebuilt from memory.

Billable hours are the hours of work you can charge a specific client for, recorded against that client and multiplied by an agreed rate. Everything else you do during a working day, from invoicing to chasing leads, still costs you time but never appears on anyone’s bill.

People get this wrong in two directions. A few treat every hour at the desk as billable and then wonder why clients push back on invoices. Many more undercount. They log the big blocks of client work from memory at the end of the week and lose the short calls, the quick email fixes and the ten minutes spent rereading a brief before a meeting. The definition is simple. The record keeping is where it breaks.

A note before going further: this guide is published by Dayflow, a Mac app that is our product, and Dayflow does not bill time. The tool details near the end come from a comparison of each vendor’s own documentation, checked on October 4, 2026.

The short version

• A billable hour is time spent on work a client has agreed to pay for, under the terms of your contract.
• Non-billable hours are real work too: admin, sales, learning, internal meetings. Clients pay for them indirectly, through your rate.
• Most billing happens in increments, commonly six minutes (a tenth of an hour) or fifteen minutes, so the way you round matters.
• Utilization is billable hours divided by available hours. It shows how much of your working time turns into revenue.
• The hard part is not the math. It is capturing time while it happens instead of reconstructing it on Friday afternoon.

What are billable hours, exactly?

A billable hour is defined by an agreement, not by effort. If your contract says you charge for research, drafting and client calls, those are billable. If it says travel is billed at half rate, travel is partly billable. If it is silent on something, you are guessing, and guesses tend to turn into disputes.

Every billable entry has five parts:

1. Client - who pays.
2. Project or matter - which piece of work it belongs to.
3. Activity description - what you actually did, in words the client will recognize.
4. Duration - how long it took, usually expressed in increments.
5. Rate - what an hour of that activity costs, which can differ by person or task.

Leave out any of these and the hour becomes hard to invoice. A duration without a description looks padded. A description without a project ends up in the wrong bill.

Billable hours matter even when you do not charge by the hour. On a fixed-fee or retainer project, the hours you spend tell you whether the fee was right. If a project you priced at the equivalent of 30 hours took 50, the next quote needs to change, and you only know that if you tracked it.

Billable vs non-billable hours, hours worked and utilization

These terms get used interchangeably, and they should not be.

Term	What it means	Example
Billable hours	Time chargeable to a client under the agreement	Writing the client’s onboarding emails
Non-billable hours	Work that serves the business but no single client	Bookkeeping, updating your portfolio
Hours worked	All working time, billable plus non-billable	First email of the day to last
Billed hours	Billable hours that actually appear on the invoice	Billable time minus write-downs
Utilization	Billable hours as a share of available hours	25 billable of 40 available is 62.5%

The gray areas cause most of the arguments:

• Internal meetings about one client’s work. Some agreements count them, many do not.
• Travel. Often billed at a reduced rate or not at all, depending on the contract.
• Fixing your own mistakes. Most people write this off. Charging for it is a quick way to lose trust.
• Learning a tool the client asked you to use. Negotiable, so negotiate it up front.

The fix for all of these is the same: decide in writing before the work starts, not when the invoice is being drafted.

How does billing in increments work?

Most people who bill by the hour do not bill by the minute. They bill in fixed increments, and the two most common are:

• Six minutes, or 0.1 of an hour. Common in legal and accounting work.
• Fifteen minutes, or 0.25 of an hour. Common among freelancers and agencies.

Here is how the same work comes out under each, assuming you round up to the next increment:

Actual time	6-minute increments	15-minute increments
4 minutes	0.1 hours	0.25 hours
7 minutes	0.2 hours	0.25 hours
20 minutes	0.4 hours	0.5 hours
47 minutes	0.8 hours	1.0 hours

Rounding up is not the only option. Some agreements round to the nearest increment, some set a minimum charge per call or email, and some cap the hours billed in a month. Your contract should say which rule applies.

The detail that trips people up is where rounding happens. If you round each entry separately, small tasks inflate quickly. Five 2-minute replies to the same client, rounded one by one at fifteen-minute increments, become 1.25 hours for ten minutes of work. Combine entries for the same task first, then round once. That is both more accurate and easier to defend if a client asks.

What is utilization, and how do you calculate it?

Utilization answers a single question: of the time you had available, how much did you bill?

Utilization = billable hours ÷ available hours × 100

The formula is easy. The denominator is not. “Available hours” can mean:

• Scheduled or contracted hours, such as a 40-hour week.
• Hours actually worked, which might be 46 in a busy week or 31 in a slow one.

The two give different answers for the same week, and neither is wrong. What is wrong is switching between them, because then the trend line means nothing. Pick one and keep it.

Two related ratios are worth knowing:

• Realization is billed hours divided by billable hours. It shows how much tracked work survives write-downs and discounts.
• Collection is the money received divided by the money billed. It shows how much of your invoicing actually turns into cash.

There is no universal right utilization number. A solo consultant who also does all their own sales and admin will have a lower figure than someone at a firm with a dedicated operations team, and that is fine. What matters is that your rate covers the gap. If only part of your week is billable, each billable hour has to carry the cost of the rest. The real hourly rate calculator is a quick way to see what your effective rate is once non-billable time is counted.

One warning: utilization measures billing, not productivity. A week spent writing a proposal that wins a six-month project might have low utilization and still be your most valuable week of the quarter.

How do you track billable hours accurately? A five-step method

The method below works whether you use timers, an automatic tracker or a paper notebook.

1. Define what counts, in writing. List the billable activities, the gray areas and how each is handled. Include the increment and the rounding rule. Share it with the client or keep it in the engagement letter.
2. Set up clients and projects before work starts. If the project does not exist in your tracker yet, the first few hours tend to land in a catch-all bucket and never get reassigned.
3. Capture time as it happens. This is the step that fails. A timer only works if you start it. A calendar only shows meetings. Either commit to the timer habit or use something that records in the background so you can sort it later. There is more on this approach in building a Mac timesheet without manual entry.
4. Review daily, not weekly. Five minutes at the end of each day to assign entries to clients and write descriptions beats an hour on Friday trying to remember what you worked on. A simple daily work log template helps if you have no system yet.
5. Round once, then invoice. Merge entries for the same task, apply your increment rule, review the descriptions as if you were the client, and only then build the invoice.

Step 3 decides the outcome of everything else. Accurate rates and careful rounding cannot recover an hour that was never recorded.

A worked example (made-up)

This is an illustration with invented numbers, not a real person or real data.

Maya is a freelance UX consultant. She bills by the hour in fifteen-minute increments, rounding up. She has two active clients.

Her timer log for one week shows:

• Client A, user research and synthesis: 13 hours
• Client B, design review and prototype fixes: 8 hours
• Proposals for a new client: 5 hours
• Invoicing and bookkeeping: 3 hours
• General email and planning: 4 hours
• An online course: 2 hours

That adds up to 35 hours, but she knows she worked about 42. During her daily review she checks her calendar and sent mail and finds what the timer missed:

• Four short calls with Client A she never started a timer for: 1.5 hours
• Quick fixes Client B requested over chat: 1 hour
• Uncategorized time she cannot place: 4.5 hours

Her billable total becomes 13 + 1.5 + 8 + 1 = 23.5 hours. Without the review, she would have billed 21 hours and left 2.5 hours of real client work off the invoice.

One hour of the Client B fixes was correcting her own error, so she writes it off. She bills 22.5 hours.

Her numbers for the week:

• Utilization, using hours worked: 23.5 ÷ 42 = about 56%
• Realization: 22.5 ÷ 23.5 = about 96%
• Unexplained time: 4.5 hours, which is the next thing worth fixing

The useful lesson is not the percentages. It is that the gap between “what I logged” and “what I did” was larger than the write-off, and she would never have seen it without a second source to check against. If you want to rough out the same split for your own week, the where does my week go calculator does the arithmetic.

What are the most common billable hours mistakes?

Reconstructing the week on Friday. Memory keeps the long blocks and drops the five-minute tasks. Those small tasks are often what fills the gap between hours worked and hours billed.

Rounding every entry up. Covered above, but worth repeating, because it is the mistake most likely to damage a client relationship.

Vague descriptions. “Work on project” invites questions. “Revised checkout flow wireframes per feedback from Tuesday’s call” does not.

Not tracking non-billable time. If you only record billable hours, you cannot calculate utilization, you cannot price fixed-fee work, and you cannot see how much of your week goes to admin.

Confusing billable with billed. Reporting billable hours as revenue overstates income whenever there are write-downs or unpaid invoices.

Treating utilization as a productivity score. It measures how much of your time was chargeable, nothing more. Pushing it up at the cost of sales and learning usually catches up with you later.

Billing meetings without counting their cost. Long recurring client calls feel productive but can crowd out deliverables. The meeting cost calculator puts a figure on a recurring meeting so you can decide whether it is worth the slot.

Tools that help with billable hours

The tools below fall into two groups. Harvest, Toggl (formerly Toggl Track) and Clockify are timer-based trackers that also handle billable rates or invoicing. Timing and Memtime record your activity automatically and let you turn it into time entries afterward. There are comparison pages for Timing, Toggl, Clockify and Memtime if you want more detail on any of them. For a wider look at every time tracker for Mac, see the guide to Mac time trackers.

Tool	What it does for this	Price
Harvest	Timers, timesheets or calendar tracking, with invoicing, online payments and expense tracking built in. Cloud service with Mac, Windows, web and mobile apps.	Free plan for 1 seat and 2 projects. Teams $9 per seat/month billed annually, or $11 per seat/month billed monthly.
Timing	Records apps, websites and documents on the Mac automatically, with billing status tracking, report rounding and, depending on plan, GrandTotal invoicing integration. Data stored locally unless you opt into sync. Mac only.	No free tier. Professional $9 per month billed annually, or $11 per month billed monthly.
Toggl (formerly Toggl Track)	Timers, timesheets and calendar integrations, with billable rates and team reports. Profitability reports and timesheet approvals on Premium.	Free for up to 3 users, but billable rates need a paid plan. Starter $9 per user/month billed annually, or $12 billed monthly.
Clockify	Timer, timesheet, calendar and an auto tracker in the desktop app. Invoicing and approval workflows on Standard and above.	Free for up to 5 users. Standard $5.49 per seat/month billed annually, or $6.99 billed monthly.
Memtime	Automatic timeline of programs, documents, emails, calls and browser tabs that you convert into time entries. Activity data stays on your device. Sync to project and billing tools from the Connect plan.	No free tier. Basic $14 per user/month billed annually, $18 billed quarterly, or $12 billed 2-yearly.
Dayflow	AI-written timeline of your day built from screen recordings stored on your Mac, exportable as Markdown. No rates, invoices or billing.	$0, MIT licensed. Optional Pro plan at $20 a month.

Dayflow is our product. It fits as a memory aid for step 3 and step 4 above: it shows what you actually did during the day so you can fill in a timesheet in another tool, but it has no billable rates, invoices, payroll approvals or team reports, and you would still need one of the tools above to bill. It runs only on macOS 14 or later, and its AI summaries can miss or misread work, so check them before relying on them; the processing options explain what stays on your Mac and what does not.

When Dayflow is the wrong choice

If your goal is to send invoices from tracked time, Dayflow is the wrong tool and Harvest is the better fit, since invoicing and payments are part of the product. If you are on a Mac and want automatic capture plus billing status and rounding in one app, Timing does that and Dayflow does not. If you run a team that needs approvals and profitability reports, look at Toggl Premium or Clockify Standard and above.

The bottom line

Billable hours are the time you can charge a client for, defined by your agreement and recorded in increments. Non-billable time is not wasted time, it is the cost your rate has to cover. Utilization tells you how those two balance, and realization tells you how much of the tracked work you actually charge.

Most of the money lost in hourly billing is not lost to low rates. It is lost to hours that were worked and never written down. Define what counts, capture time as it happens, review it daily and round once. For the billing itself, Harvest and Clockify handle invoicing, Toggl covers team rates and profitability, and Timing or Memtime suit people who would rather sort an automatic record than remember to press start.

Frequently asked questions

What counts as a billable hour?

A billable hour is time spent on work a client has agreed to pay for under your contract or engagement terms. Drafting, research, client calls and revisions usually count. Admin, sales and internal training usually do not. Gray areas like travel, internal meetings about one client's project, or fixing your own errors depend entirely on what the agreement says, so write those rules down before the work starts.

Are billable hours the same as hours worked?

No. Hours worked covers everything you do for the business, including invoicing, proposals, email triage and learning. Billable hours are only the portion you can charge to a specific client. The gap between the two is normal and necessary, since someone has to run the business. Your hourly rate has to be high enough that billable hours also pay for the non-billable ones.

What is a six-minute billing increment?

A six-minute increment is one tenth of an hour, written as 0.1. Work is recorded in units of 0.1, so a 7-minute call becomes 0.2 if you round up to the next increment. Six-minute units are common in legal and accounting work. Fifteen-minute units (0.25 hours) are also common. Your contract should state which increment applies and how rounding works.

How do you calculate a utilization rate?

Divide billable hours by available hours, then multiply by 100. If you logged 24 billable hours out of 40 available, utilization is 60 percent. The tricky part is defining available hours. Some people use contracted or scheduled hours, others use hours actually worked. Pick one definition and keep it, because switching between them makes week-to-week comparisons meaningless.

Is it ethical to round billable time up?

Rounding up to the next increment is a standard practice when the contract allows it. The problem starts when you round every tiny entry separately. Five 2-minute emails rounded up at fifteen-minute increments become 1.25 hours for ten minutes of work. Combine entries for the same task first, then round once, and follow whatever rounding rule your agreement states.

Should I track non-billable hours too?

Yes. Without non-billable time you cannot calculate utilization, you cannot tell whether a fixed-fee project made money, and you cannot see how much of your week goes to sales and admin. That last number is what you need to set a rate that actually covers your costs. Tracking it does not mean charging for it, only knowing it.

Can Dayflow track billable hours and send invoices?

No, and for billing another tool is the better choice. Dayflow writes an AI timeline of your day on your Mac, but it has no billable rates, invoices, payroll approvals or team reports. If you need to turn hours into invoices, Harvest includes invoicing and online payments, and on a Mac, Timing adds billing status, report rounding and a GrandTotal invoicing integration depending on plan.

What is the best way to track billable hours on a Mac?

It depends on whether you remember to start timers. If you do, Harvest or Toggl (formerly Toggl Track) work well and run on Mac, web and mobile. If you forget, an automatic tracker like Timing or Memtime records your activity in the background so you can assign it to clients later. Timing is Mac only; Memtime also runs on Windows and Linux.

Do fixed-fee projects still need hour tracking?

Usually yes, just for a different reason. You are not charging by the hour, but you still need to know how many hours the project consumed to see whether the fee was profitable. Without that, you will keep quoting the same fee for work that takes twice as long as you think. The hours become pricing data instead of invoice lines.

What is the difference between billable and billed hours?

Billable hours are the time you could charge under the agreement. Billed hours are what actually appear on the invoice after write-downs, discounts or caps. If you logged 20 billable hours but wrote off 2 for fixing your own mistake, you billed 18. The ratio of billed to billable is often called realization, and it shows how much tracked work turns into charges.