Several Japanese words for "interest"

[shimewaza]

Off the top of my head, I can think of three Japanese words for "interest" (as in the money kind): 利子、金利、利息. Then there is 利率, which I guess has the specific meaning of "interest rate". I'm wondering to what degree do the meanings of these words overlap, or on the other hand, to what degree is the choice of word determined by specific context? Any insight would be appreciated.

[keatonatron]

It feels to me like I've seen 利息 the most out of all those. The dictionary says it's the exact same as 利子, so I don't think there are any differences. 金利 can mean the interest, but it can also mean the interest rate.

And 興味 means interest, but it is totally unrelated

[Mukade]

Interest rates for a loan would be 金利.

I know, because I'm paying out the arse for one!

[okoma]

interest rate : 金利、利率
利率 is expressed with %, but 金利 is not.
When 利率 is 1%, 金利 is 0.01.

interest :　利息、利子
In the financial institutions case, 利息 tends to be used as legal fruits what it gain when it loan the money.
Similarly, 利子 tends to be used as legal fruits what people gain when they bank the money.
But, it is OK, you use them with no distinction.