A billable hours calculator converts a matter’s time entries into a clean fee summary in seconds. Law firms bill multiple rate tiers on a single matter — partners, associates, and paralegals each at a different rate — and clients want to see the breakdown plus the effective blended rate. This tool sums hours per timekeeper, applies each rate, and reports per-tier subtotals, the total fee, and the average rate across the work.
How it works
The arithmetic is straightforward but easy to fumble across many entries. For each timekeeper the fee is rate × hours. The matter total is the sum of every timekeeper’s fee. The blended rate — the headline figure clients ask for — is total fee ÷ total hours, the single average hourly rate once all tiers are combined.
Legal time is conventionally recorded in tenths of an hour, where 0.1 equals six minutes. The tool accepts decimal hours directly, so a 0.3 entry (eighteen minutes) and a 2.5 entry (two and a half hours) both sum exactly. An optional write-down percentage reduces the gross fee to a net amount, modelling a courtesy discount or a write-off of unproductive time.
Total fee = Σ (rate × hours); blended rate = total fee ÷ total hours.
Example and notes
A matter has a partner at $550/hr for 3.2 hours, an associate at $320/hr for 8.5 hours, and a paralegal at $150/hr for 5.0 hours. The subtotals are $1,760, $2,720, and $750, for a total of $5,230 over 16.7 hours — a blended rate of about $313/hr. Apply a 10% courtesy write-down and the net fee falls to $4,707.
Use the blended figure when proposing a single rate to a price-sensitive client, and the per-tier breakdown for the formal invoice. All figures stay in your browser; copy the summary before closing the tab.
Reading the blended rate in context
The blended rate is not just an accounting figure — it has strategic uses:
- Alternative fee arrangements — clients increasingly ask for fixed fees or capped fees on a matter. If your blended rate for comparable past matters is $290/hr, a fixed-fee proposal for a similar matter can be anchored to predicted hours × that blended rate, then adjusted for risk.
- Benchmark against market rates — surveying whether your blended rate is competitive for the matter type and jurisdiction is easier when you express the whole matter as a single hourly figure rather than a tiered breakdown.
- Staff mix optimisation — if two matters have the same total fee but one is 60% partner time and the other is 60% paralegal time, the first has a much higher blended rate. You can use this tool to model how changing the allocation of work between timekeepers changes the blended cost.
Common billing mistakes this tool helps avoid
- Mixing up tenths and minutes — law firms use tenth-of-hour increments; 0.3 is 18 minutes, not 30. Entering hours as true decimals (1.5) and tenths-notation entries (0.3) in the same matter is a frequent source of billing errors.
- Forgetting write-downs in the projection — many firms apply routine courtesy discounts or write off non-productive time after the matter closes. Including a write-down estimate before quoting the client leads to fewer surprises.
- Using different rates for the same timekeeper on a single matter — some billing software allows rate exceptions mid-matter. This calculator treats each entry as a separate timekeeper, so you can model those rate changes explicitly by entering the same person twice at different rates for different date ranges.
Notes on time entry
Legal time entries are typically rounded up to the nearest 0.1-hour increment, so a 4-minute phone call is billed at 0.1 (6 minutes). Some clients negotiate 0.25-hour (quarter-hour) minimums instead, which this calculator also accommodates — simply enter 0.25 as the minimum time unit for the affected entries.