If you bill by the hour like I and many (most?) other attorneys do, the start of a new year means the resetting of your personal odometer — zero hours to date out of the total number of hours that you plan to bill during the year. Many of us divide our billable hour goal by 12 to have a rough sense of how much we need to bill a month, or divide by 52 to have a rough sense of how much we need to bill a week, but of course that is not very precise because it doesn't not take into account vacation days, personal days, holidays, etc. Elliott Mason, a non-attorney who holds a Ph.D. from MIT, is a patent agent at the Boston law firm Occhiuti & Rohlicek LLP. A few months ago, he created an iPhone app called BillablePlan that helps you to perform precise billable hour calculations. The app costs a $2, or you can get a free version of the app that includes ads and is missing an auto-update feature. Mason sent me a free review copy of the full version of the app so that I could check it out.
To use the app, you first need to tap on the Settings button at the bottom right and give the app your data. This includes your billable hours goal for the year, the number of day that you work in a workweek (presumably five), the hours that you have already billed this year, the number of firm holidays remaining in the year and the number of personal days left in the year. Then you select a Calculation Period for all of the calculations that the app will make for you. The most useful one is "Auto Update" (available in the paid version of the app) which means that every time you start the app it makes calculations from the current date to the end of the year. Another useful one is "Full" which makes calculations for the entire year, regardless of how many days have already passed. There are some other things you can adjust in Settings for more advanced calculations.
Once you have finished in Settings, you can start making some calculations using the other three buttons at the bottom of the screen.
The Vacation button lets you calculate how many vacation days you can take in a year based on how many hours you plan to work, on average, every workday. For example, if I tell the app in Settings that my annual billable hour goal is 2000 hours and that I have already billed 80 hours this year, the Vacation calculator tells me (as you can see below) that as of Jan. 19th, if I work an average of 8.5 hours every workday I can take 10 vacation days on top of my 12 holiday/personal days. If I instead tell the app that I will bill an average of 9 hours a day, the app tells me that I can take 23 vacation days.
On the other hand, if in Settings I tell the app that I plan to bill 1800 hours this year, I can now bill 8 hours each workday and still get 21 vacation days in addition to holidays/personal days.
The second calculation button is called Work Hours, and it performs a calculation from the other direction — if you plan to take a certain number of vacation days, how many hours do you need to bill on each of your workdays? In the next example, with a 2000 billable hour goal selected in the Settings, I tell the app that I plan to take 10 vacation days. The app tells me that to do that I will need to bill 8.5 hours a day. If I instead tell the app that I'd like to have 15 vacation days, the app tells me that I will have to bill 8.7 hours every workday to meet my 2000 billable hour goal.
Finally, the app has a Progress button that simply shows how many days are remaining in the year and— based upon what you put in the Settings — how many hours you have left to bill in the year.
If you are interested in being able to make precise billable hour calculations, BillableHours is a helpful app. You can download the free version to get a feel for how the app works, and if you like it, you'll definitely want to pay $2 to get rid of the ads and to enable the useful Auto Update function.