Billable Hours Calculator
Split total work hours into billable and non-billable: total = hours/day x days; billable = total x billable %; the rest is non-billable.
Input Data
Results
At a glance:Billable hours are work hours you can invoice clients; the rest are non-billable (admin, meetings, training, marketing). total = hours/day x days; billable = total x billable %; non-billable = total - billable. At 8h/day, 20 days, 75% billable: total 160, billable 120, non-billable 40. The billable % is also the utilisation rate — a key metric for hourly-billing professionals. WARNING: High utilisation is not always better; balance it with client development and rest.
Formula
Total hours = hours per day x working days.
Billable hours = total hours x billable %.
Non-billable hours = total hours - billable hours.
$$\\text{Total} = h \\times d$$$$\\text{Billable} = \\text{Total} \\times u,\\quad \\text{NonBillable} = \\text{Total} - \\text{Billable}$$How to Use
- Enter average hours per workday and the working days in the period.
- Enter the share of hours that are billable.
- View billable and non-billable hours.
FAQ
How are billable and non-billable hours calculated?
Step 1: total hours = hours/day x working days (e.g. 8 x 20 = 160). Step 2: billable = total x billable % (160 x 75% = 120). Step 3: non-billable = total - billable (160 - 120 = 40). Billable = time spent on client-chargeable work; non-billable = admin, meetings, training, marketing, pitching. The split is essential for anyone billing by the hour.
What does billable % (utilisation) mean — higher is better?
It is the share of your time that generates direct revenue. Higher usually means more income potential. But pushing it too high squeezes client development, training and rest, hurting long-term sustainability and risking burnout. Aim for a reasonable, sustainable target rather than maximum.
How do I use this to manage time and income?
Set a baseline, then reverse-engineer income targets (billable hours x rate = revenue). Analyse non-billable time: keep what is valuable (pitching, training), cut or automate what is low-value (repetitive admin). Adjust the billable % to plan capacity and pricing. Pair with hourly-rate and income calculators.
How do I turn rate and utilisation into monthly/annual income?
Monthly billable hours = hours/day x working days x utilisation. At 8h/day, 20 days, 75%: 120 billable hours. Income = 120 x rate. At HK$800/h that is HK$96,000/month, about HK$1.15m/year (adjust for time off). Levers: raise rate, raise utilisation, or add hours — rate and utilisation are more sustainable than longer hours. Note this is gross; deduct costs, profits tax/salaries tax and bad debts.
What is a reasonable utilisation rate?
No universal number — it varies by field and seniority. But 100% is neither realistic nor healthy; everyone needs non-billable time for pitching, quotes, admin and rest. Build your own baseline, then raise it gradually. Improve it by cutting low-value admin via tools/outsourcing, not by cutting rest or learning.
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References
Content review: Calculatorism Finance Team. Results are for reference only; please refer to the relevant authorities for the official figures.