I usually find a sample a few semitones off, or exactly in the key I want. Also, going a 5th above the root note is okay too, especially if you're using a powerful bass.

I usually drag my sample into a drum rack in ableton, then throw a spectrum on it, and see where the lowest peaking frequency is, for example a kick in E will be around 41hz. If you cant quite get it off of that, then transpose the kick sample up an octave, and its usually easier to tell.

If that doesn't work, or its still unclear, throw an EQ on, cut away all the higher frequencies, and play a sine wave alongside the kick.

Ableton's spectrum analyzer has the notes mode where you can see the notes.. I imagine most other eq's have a similar feature.

Also because i switch between daws. ableton & Fl.

I know this can seem counter-intuitive and unnecessarily difficult in the age of forums where you can ask a quick question and get quick answers, but....do not underestimate the power of the owner's manual!   A simple "control/command - F" can usually get you where you need to be.

If you use FL Studio, you can drag the drum samples like kick drum and detect the pitch. also you can adjust it like the key of your song.

If you're a DJ and have Mixed In Key, you can also import all your samples and search them by key that way.