Billable Hours Calculator
Calculate billable fees from hours worked and hourly rate, with optional billing-increment rounding (6-minute tenths).
How to use this tool
- Enter hours worked, hourly rate and billing increment in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your billable fee and the full breakdown beneath it.
This is an estimate, not legal advice. Laws vary by jurisdiction and individual circumstances. Consult a qualified attorney before making any legal decisions.
Estimate attorney or consultant fees by entering the time spent and the hourly rate. The calculator rounds up to the nearest billing increment (commonly 6-minute tenths of an hour).
⚠ This tool provides general estimates for education only and is not financial, tax or legal advice. Figures may not reflect your situation — verify with a qualified professional.
Formula
Rounded hours = ceil(hours ÷ increment) × increment
Billable fee ($) = rounded hours × hourly rate
How it works
This calculator rounds actual hours worked up to the next billing increment using a ceiling function, then multiplies by the hourly rate to produce the billable fee. The 0.1-hour (6-minute) increment is the legal profession's standard tenth-of-an-hour unit, though the tool accepts any positive increment. Rounding is always upward, which is standard practice; partial increments are never discarded in the client's favour.
Worked example
- Inputs: 1.5 hours worked, $300/hr rate, 0.1-hour billing increment.
- Rounded hours: ceil(1.5 ÷ 0.1) × 0.1 = ceil(15) × 0.1 = 15 × 0.1 = 1.5 hours.
- Billable fee: 1.5 × $300 = $450.
Rounded hours: 1.5 h; Billable fee: $450.
Common mistakes to avoid
- Forgetting to apply billing-increment rounding before multiplying by the rate -- 0.4 hours rounds up to 0.5 in a 6-minute-increment system, changing the fee even before the rate is applied.
- Entering decimal hours (e.g., 1.5) when the billing system expects separate hours and minutes, causing either over- or under-billing.
- Using a blended rate when different tasks on the same matter carry different rates -- the calculator assumes one rate for all hours entered.
Key terms
- Billing increment
- The minimum time unit charged to a client, most commonly 0.1 hour (6 minutes) in legal billing.
- Ceiling rounding
- Rounding a number up to the next multiple of the chosen increment, ensuring no partial unit is absorbed by the practitioner.
- Hourly rate
- The fee charged per hour of professional service, agreed upon in the engagement letter or contract.
- Time entry
- A record of a specific task performed and the duration spent on it, used to compile billable hours.
Frequently asked questions
- What is a billing increment?
- A billing increment is the minimum unit of time an attorney charges for. The most common is 0.1 hours (6 minutes). So even a 2-minute phone call is billed as 0.1 hours.
- How do I convert minutes to tenths of an hour?
- Divide minutes by 6 and round up. For example, 20 minutes ÷ 6 = 3.33, rounded up = 4 tenths = 0.4 hours.
- Does every attorney bill in 6-minute increments?
- No — billing practices vary. Some attorneys bill in 15-minute or 30-minute blocks, or in full hours. Always confirm the billing increment with your attorney upfront.