In one panel in 犬夜叉1, the character says:
よし、こんなもんか。
He says that after digging up a hole to hide his fellow.
I suppose that もんか is a contraction of ものか. As far as I know, that should carry a meaning of irony (as if this…). It doesn’t, however, fit there. It was his idea to dig that hole, there was no discussion about it, no objections. No conversation on that topic preceded.
Another meaning of ものか I found was to express a surprise. That fits there even less.
In the context, something like
So, this should be enough. (The hole is big/deep enough already.)
would fit there. But that doesn’t match the Japanese version. Or does it? Is there some meaning of the ものか (or even just もんか) I’m just unaware of?