This is an estimate, reported by large media organizations:
From the Council on Foreign Relations:
In President Obama’s last year in office, the United States dropped 26,171 bombs in seven countries.
and
Most (24,287) were dropped in Iraq and Syria. This number is based on the percentage of total coalition airstrikes carried out in 2016 by the United States in Operation Inherent Resolve (OIR), the counter-Islamic State campaign. The Pentagon publishes a running count of bombs dropped by the United States and its partners, and we found data for 2016 using OIR public strike releases and this handy tool.* Using this data, we found that in 2016, the United States conducted about 79 percent (5,904) of the coalition airstrikes in Iraq and Syria, which together total 7,473. Of the total 30,743 bombs that the coalition dropped, then, the United States dropped 24,287 (79 percent of 30,743).
This statistic is still new, and it hasn't been disputed or accepted yet. It is possible that the methodology will have issues that are not immediately visible. But if the question is if this was made up just for Facebook, then no, it is not a made-up statistic. It has some basis in reality and has been accepted by real media organizations.
Note that
Sounds about right for a president who bombed 7 nations and became the first in U.S. history to be at war every single day of his eight year administration.
Is attributed to Ron Paul in the Zero Hedge post.