Billable Hours Calculator
Project your billable revenue from your rate and schedule, and convert minutes into tenth-of-an-hour billing increments with the 6-minute chart below. No signup.
Your schedule
Runs entirely in your browser — nothing is sent anywhere.
Your billable projection
Tip: utilization matters — if only 6 of an 8-hour day is billable, that's 75% utilization. Raising it even slightly compounds across the year.
The Hammer Lex captures every tenth of an hour with live timers and timesheets, then turns it straight into invoices and profitability — no manual math.
See automated time & billing6-minute billing increment chart
Most firms bill in tenths of an hour, where each tenth is 6 minutes. Round each time entry to the increment that contains the minutes worked.
| Minutes worked | Billable time (decimal) |
|---|---|
| 1–6 min | 0.1 hour |
| 7–12 min | 0.2 hour |
| 13–18 min | 0.3 hour |
| 19–24 min | 0.4 hour |
| 25–30 min | 0.5 hour |
| 31–36 min | 0.6 hour |
| 37–42 min | 0.7 hour |
| 43–48 min | 0.8 hour |
| 49–54 min | 0.9 hour |
| 55–60 min | 1.0 hour |
How to calculate billable hours
Billable hours are the hours you can charge to a client, recorded in standard increments. To project income: multiply billable hours per day by working days per week and working weeks per year for annual billable hours, then multiply by your rate for revenue.
The gap most people miss is utilization — the share of worked hours that are actually billable. An eight-hour day rarely yields eight billable hours; meetings, admin, and business development eat into it. That's why a 1,800-hour billable target can mean 2,400+ hours at the office, and why accurate time capture (not memory at day's end) protects real revenue.
Frequently asked questions
What is the 6-minute billing increment?
Firms bill in tenths of an hour; each tenth is 6 minutes. 1–6 min = 0.1, 7–12 = 0.2, up to 1.0 for a full hour (see chart above).
How many billable hours per year are realistic?
Common targets run 1,700–2,000. Because not every worked hour is billable, hitting those numbers requires considerably more total hours — utilization is the lever.
How do I bill more without working more?
Improve capture and utilization: track time as you go rather than reconstructing it, reduce write-offs, and offload admin. See how The Hammer Lex helps.
Capture every tenth of an hour
Live timers, timesheets, custom rates, and one-click invoicing — then see profitability per matter. All in The Hammer Lex.
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