It depends on the context. It can be “proportionally”, “up to a point” or “to some extent”.

An unwieldy translation would be “making the necessary adjustments”. The idea is that in a comparison there are some differences in the comparands, but if you allow for those differences then the comparands may be seen to be similar.

If you’re in a formal context it would be better to use the latin phrase: mutatis mutandis

Additionally you may use “all things considered” which, arguably, is often used as “toutes proportions gardées” when about quantities, as in this example:

Actually, Fitch thinks his family is doing fine right now, all things considered.

Example from here.