According to the latest annual report from the Stockholm International Peace Research Institute (SIPRI). Total world military expenditure rose to $1739 billion in 2017, a marginal increase of 1.1 per cent in real terms from 2016.
The full text can be downloaded from the website. This also provides free access to the SIPRI Military Expenditure Database which has time series on the military spending of countries for the period 1949–2017.
Since 1981 the UN has also maintained a file of military expenditure per capita. Consult the sources and methodology for definitions.