It will usually be announced sometime near the end of November but more likely around the beginning part of December each year.
Don't forget to use the free mileage log from this website. It is required by the IRS that you keep a record of the mileage and other possible deductions, though limited, of your trips.
Download a mileage log here and take a look at it for details. It's simple really, and you can print as many as you would need as you need them or save a copy on your computer for future reference.
If your vehicle is in a good condition, and best if you don't owe any money on it then you can do well with the mileage allowance / deduction.
It might be considered reasonable to look at the alternatives with the Vehicle Depreciation method.
If it has a low insurance cost, this could be even better.
The vehicles that also get great MPG do even better because you save on all costs and get the same deduction as if you had a high over head vehicle!.
For 2017 it is 53.5 cents per mile but the year 2016 had a business mileage rate that was actually higher at $0.54 per mile.