How many subcamps did the Dachau concentration camp have?

In the historical sources there is no uniform designation used for the
subcamps (sometimes they are called work details, labor camps, external work
details, subcamps and sub work details). Recent studies have established the
term “subcamp” as a uniform designation for those locations outside the grounds
of a concentration camp where prisoners were accommodated and forced to work.
In contrast, when prisoners had to march to a specific site to work, but
returned to the main camp in the evening, research now speaks of a “work
detail”.

The subcamps attached to the main Dachau concentration camp were
extremely divergent: there were very small camps with just one or two
prisoners, but also large subcamps for several thousand prisoners. The historian
Sabine Schalm has therefore proposed a further conceptual differentiation:

She calls camps with fewer than 500 prisoners “external work details”.
They did not have any complex camp structure, important administrative
procedures were organized and carried out by the main camp office. The
prisoners and guards were under the command of a single detail leader. Prisoner
accommodation was provisional in character, often the prisoners were housed in
existing factory buildings, garages, or huts.

In contrast, Schalm calls camps with more than 500 prisoners “subcamps”:
they had a complex administration structures and offices, meaning that, unlike
the external work details, they could be administered directly on site with a
relatively large amount of autonomy. They had their own command staff, headed
by a camp leader, who reported directly to the commandant of the main camp and
had several detail leaders under his command. The prisoners were accommodated
in structures especially built for this purpose and located within a guarded
enclosure.

Literature tip: Sabine Schalm, Überleben durch
Arbeit? Außenkommandos und Außenlager des KZ Dachau 1933 – 1945, Berlin 2012
(second revised edition).