resolve/refinerycms — comment on commit 6e6a5f62c1ba4449fcf2098ee4670a19fcea039e
File:  line 0
By resetexistence:

Because it is configured on a byte level and not a megabyte level. If you want the maximum upload size to be 50KB then you would see an error like .05 megabytes - etc.

Also web servers measure this in bytes and not megabytes as well.