Calculating billable hours: a step-by-step guide with examples

Key takeaways

• Four steps: track time per client, separate billable from non-billable, multiply by your rate, and invoice with an itemised breakdown.
• The line between billable and non-billable is scope. Work inside an agreed project is billable. Work that runs your business is not.
• Small favours that never get logged are how scope creeps. 14 unbilled hours on each of six projects at $100 an hour is $8,400 a year.
• Set your rate from your target income. $120,000 a year, plus $40,000 of costs, over 1,500 billable hours, is a floor of about $107 an hour.
• Put an hour budget on each deliverable in the scope, and agree that anything over 2 extra hours becomes a written change request.

What are billable hours?

Billable hours are the time you can charge a client for: design, development, revisions, calls about the project. Non-billable time is everything that keeps the business running but never appears on an invoice. Both take up your week. Only one pays for it.

The line is scope

If the work is inside a project the client agreed to, it is billable. If it serves your business rather than a client, it is not. The trouble is that both feel the same while you are doing them, which is how unrecorded overhead eats into the margin without anyone noticing.

Where the non-billable time goes

Writing proposals. Chasing overdue invoices. Rewriting the same follow-up email for the fifth time. None of it is billable, and all of it is part of running client work. Track it anyway, per client, because you cannot price for time you cannot see.

How do you calculate billable hours, step by step?

1. Track hours per client as you work

Log time as you go, per client and per task, not from memory at the end of the week. A timesheet rebuilt on Friday tends to miss the short calls and small fixes that never felt worth recording, and fifteen minutes here and there across five clients adds up to real money.

2. Choose a rounding rule

Pick one and put it in your contract. Most small firms round to 6 or 15 minutes, sometimes with a minimum per entry. Rounding to 15 minutes means a 7 minute call bills as 15, so quick client contact is not quietly given away.

3. Decide what to bill and what to write off

Not every tracked hour is billable. Bill what is inside the agreed scope. Write off internal admin, rework caused by your own mistakes, and anything you would be embarrassed to put on an invoice. Decide per time entry and note why, so that patterns show up over time.

A worked example: one week, two clients

At $100 an hour, that week invoices $1,650. The write-offs are the honest part of the calculation. The rounding rule is what stops small tasks from disappearing.

In Projectous, each time entry is marked billable or not, and the hours on an invoice can differ from the hours tracked, so a write-off is a decision you can see rather than a gap. It does not round time for you yet. Round when you build the invoice.

How do you set your hourly rate?

Work back from the income you need

Start from what you want to earn, not from the rate you feel comfortable quoting. Say you want $120,000 a year before tax and your business costs $40,000 a year to run. You need $160,000 from clients. Over 1,500 billable hours, about 30 a week for 50 weeks, that is roughly $107 an hour.

That figure is a floor. Below it, you are paying for the client’s work yourself. And if you cannot fill 1,500 hours, the floor rises: at 1,200, it is $133.

One rate or several

A single rate across every client and task is simple to quote and explain. It also undercharges your most senior work and overcharges routine tasks. Different rates per client or per kind of work let you price a demanding retainer differently from a small project, which is often where a project’s profit is won or lost. Two or three tiers is usually enough. Ten is hard to keep straight.

Apply the rate

Multiply billed hours by the rate, after rounding by the rule in your contract. Six minute increments, a tenth of an hour, are common in legal and consulting work. Quarter hours are simpler. Either is fine if the client knew which before the first invoice.

How does loose time tracking cause scope creep?

Scope creep rarely arrives as one big request. It arrives as fifteen minute favours that never get logged, so the work never reaches an invoice.

A worked example: 14 hours nobody billed

You agree a fixed-scope website build at $100 an hour. Along the way the client asks for a logo tweak, a copy edit, one extra page, and quick help with their email. Each is small enough to just do. Two weeks later you have spent 14 hours on work that was never in the scope and never reached a timesheet. That is $1,400 of work given away on one project.

Why it slips through

You finish a call, the client mentions something small, and you fix it straight away because the file is already open. By the time you log your hours that evening, the fifteen minutes are gone. Nobody records what felt like a favour. Across four or five clients and a month of goodwill, you are carrying a second workload that pays nothing.

The fix is not willpower. Log the time the moment the work happens, out-of-scope work included, so you can see it and then decide whether to bill it, absorb it, or push back.

What it costs in a year

14 unbilled hours on each of six projects at $100 an hour is $8,400. Two more hours a week of unlogged admin and follow-ups, at the same rate, is another $10,400. Together that can be the difference between a profitable year and breaking even, and most owners only find out when they compare hours tracked with hours invoiced.

How do you keep billable hours inside the scope?

Put an hour budget in the scope

Do not write “redesign homepage.” Write “redesign homepage: 12 hours.” When the budget runs out, the conversation starts from a number the client agreed to.

Set a change request threshold

Agree in advance that anything over 2 hours of extra work becomes a written change request with a price. Smaller favours keep the goodwill. Anything bigger gets scoped. Because the rule was agreed before the work started, applying it does not feel pushy.

Compare hours with budgets every week

Once a week, look at tracked hours against the budget for every client, and deal with anything over or stuck. Projectous sets a budget on each contract, counts tracked hours against it, and tells you when a contract goes over. The weekly look is still yours to do. No tool makes that habit for you.

How do you turn billable hours into an invoice?

Group hours so the client can see what they paid for

“40 hours, $4,000” invites questions. Group the hours by task or deliverable instead: “Homepage redesign, 11 hours.” “Revisions from client feedback, 3 hours.” Itemised lines justify the total, cut down the back and forth, and make extra work visible as its own line instead of hiding it in a lump sum. Before you send, check each line against the agreed scope.

Invoice on a fixed schedule

Invoicing “when things calm down” is how invoices end up three weeks late. Pick a schedule, such as the 1st and 15th, or every Friday for weekly retainers, and close timesheets the same day so no hours slip into the next cycle. A fixed schedule means you chase the occasional late invoice rather than rebuild a month of unbilled work.

What should you look for in time tracking software?

Five things to judge a tool on

• Hours get recorded without you chasing anyone.
• Work that is stuck or over budget comes to you.
• Invoices are built from the hours already tracked.
• You can see whether each project made money.
• Setup takes days, not a consulting engagement.

Where Projectous fits

Projectous is built for small studios and freelancers doing work for several clients at once. Time, contracts and invoices share the same tracked hours, budgets warn when they are crossed, and work that has stalled is surfaced rather than found. It is not built for large firms that need detailed capacity planning or billing across several legal entities, and it does not replace your accounting software. At 20 people or more, with dedicated operations staff, it will feel light.

When a heavier tool makes sense

Productive, Teamwork.com, Scoro and Accelo serve agencies that want deeper reporting and broader operations. If one of them feels like more than you need for a team of two to ten, that instinct is usually right. Pick the lightest tool that stops billable hours leaking. If you are comparing, here is Projectous against Scoro.

Questions people ask

How many billable hours are realistic in a 40-hour week?

Plan for 25 to 30. The rest goes on proposals, admin, sales calls and chasing invoices, none of which a client pays for. If your rate assumes 35 billable hours a week, you are undercharging from the start. Track the real split for a month before trusting any estimate.

Six minute increments or quarter hours?

Either, as long as it is in the contract. Six minutes reads as precise. Quarter hours are simpler to explain and protect you more on short calls, because a 7 minute call bills as 15.

Do I bill for fixing my own mistakes?

No. Rework caused by your own errors is a write-off, and billing it costs trust you cannot buy back. Log it anyway. If rework keeps appearing on one client’s timesheet, the problem is in your scoping or checking, not their budget.

Do I bill for work before the contract is signed?

Usually not, unless you agreed otherwise. If you want discovery paid, say so before you start: “Discovery is billed at $X, credited against the project if you go ahead.” Log those hours even when they are written off, because they are real costs that belong in your rate.

What is the difference between billable hours and utilisation?

Utilisation is the share of your working hours that end up billable. Billable hours are the count you invoice. Watch billable hours against each project’s budget, because that is where scope leaks show first. A healthy utilisation figure can still hide unbilled out-of-scope work.