Billable Hours Calculator
How many hours you need to bill at your rate to reach a target income after expenses, fees and an optional tax reserve.
Your target
Filled in with example values. Replace them with your own.
Your target and rate
Your time
Business costs
Optional
A percentage of your profit to put aside for taxes. Choose it yourself or ask an accountant.
Currency symbol
Results update as you type.
Result
Billable hours needed: 19.8 a week (909.5 a year) at $75.00 an hour, invoicing $68,210.53 a year
Bill at least
19.8hours a week
- Billable hours a year
- 909.5 h
- Billable hours a monthAverage month
- 75.8 h
- Share of your working timeOf 40 hours a week
- 49.4%
- Revenue to invoice a year
- $68,210.53
What the hours need to cover
- Personal income
- $60,000.00
- Business expenses
- $4,800.00
- Platform and payment fees5% of invoiced revenue
- $3,410.53
- Revenue to invoice
- $68,210.53
How it’s calculated
Revenue to invoice a year
income + tax reserve + expenses + fees = $68,210.53
Divide by your rate
$68,210.53 ÷ $75.00 = 909.5 h
Per working week, rounded up
909.5 h ÷ 46 = 19.8 h
Share of working time
19.77 h ÷ 40 h = 49.4%
How the billable hours calculator works
Your rate is fixed and your target is known, so the question is how much work it takes. The calculator adds up what your invoices must cover in a year (your personal income, an optional tax reserve, business expenses and the fees taken from each invoice) and divides that by your hourly rate.
Dividing by your working weeks gives the hours to bill each week. If you also enter the hours you work, it shows what share of your working time has to be billable.
The formula
Revenue to invoice = (Income ÷ (1 − Tax reserve %) + Expenses) ÷ (1 − Fee %)
Billable hours a year = Revenue to invoice ÷ Hourly rate
Billable hours a week = Billable hours a year ÷ Working weeks
Billable share = Billable hours a week ÷ Hours worked a week
Worked example
A developer charges 75 an hour and wants to keep 60,000 a year. Expenses are 300 a month plus 1,200 a year, the payment provider keeps 5%, and they take 6 weeks off.
- Expenses: 300 × 12 + 1,200 = 4,800
- Revenue to invoice: (60,000 + 4,800) ÷ 0.95 = 68,210.53
- Billable hours: 68,210.53 ÷ 75 = 909.47, rounded up to 909.5 hours a year
- Per week: 909.47 ÷ 46 = 19.77, rounded up to 19.8 hours a week
- Out of a 40-hour week, that is about 49.4% billable time
Assumptions and limitations
- Every working week is treated the same. Busy and quiet periods even out over the year in this model.
- Fees are a percentage of each invoice. Fixed per-payment charges are not included; add them to expenses if they matter.
- The tax reserve is a share of profit that you choose. It is not a tax calculation or tax advice.
- The result is the work needed, not a guarantee that the work will be available.
Frequently asked questions
How is this different from the Freelance Rate Calculator?
They answer opposite questions. The Freelance Rate Calculator starts from the hours you can bill and tells you what to charge. This calculator starts from the rate you already charge and tells you how many hours you need to bill.
What counts as a billable hour?
An hour a client pays for. Time spent on proposals, invoicing, admin, marketing and learning is real work, but it is not billable unless a client is paying for it.
What if the result is more than the hours I work?
Then the target cannot be reached at this rate in the time you have. The calculator warns you. You can raise your rate, lower your target or costs, or plan more working weeks.
Why are hours rounded up?
Rounding down would leave you slightly short of your target, so hours are rounded up to the next tenth of an hour.
How should I choose the tax reserve?
It depends on where you live and your situation, so the calculator does not suggest one. Choose the share of profit you want to set aside, ideally with an accountant’s advice. It is a planning figure, not a tax calculation.