Can an Inspiron 3910 fit my Geforce RTX3060 inside it?

It's more than just fitting inside the case. What size PSU does your the Inspiron 3910 have and what's the "minimum recommended" PSU size for that exact RTX 3060 card? 

@RoHe​ It requires 550W. I have a 650W PSU that will handle that GPU in my current (old) Inspiron. It's the standard size, I think, so it should fit in a new one too. But I don't know if the GPU itself will fit. That's my chief concern.

Hang on a sec...The stock PSU in the Inspiron 3910 is either 180 W, 240 W or 300 W.

So unless you've upgraded the PSU in this Inspiron, you won't be able to run any GPU that requires a 550 W PSU.

If you don't know what PSU you have in your Inspiron 3910, go to the Support page and enter the Service Tag. (Don't post Service Tag here.) 

When the site recognizes your PC, click the link on right side of the page under Quick Links to open the system config window. Scroll down that list and see exactly which PSU you have...

I suspect the Inspiron 3910 PSU is customized so you probably can't use PSU from old PC. Read this thread. And this one which suggests you might be able to install a 460 W PSU, if you can even buy it from Dell or elsewhere.

@RoHe​ I haven't purchased the Inspiron 3910 yet, I'm only going to do it if the rtx3060 GPU will actually fit in there. Can you help me figure out the sizes? I don't want to buy it and have to return it. Again, the GPU is 9.25"x4.9".

I do intend to upgrade the PSU in the new Inspiron, that's what I'm saying. I'm going to upgrade the stock one to a 650W, same as I did with my old Inspiron 3670. But I'll only do it if my rtx3060 gpu will fit in the new Inspiron 3910, because I don't want to buy a new GPU.

Read the edit to my previous post in bold.  You probably cannot upgrade the PSU to 650 W.....

@RoHe​ Well, if I have to I'll buy a new PSU. I presume there are some higher power PSUs out there that must be able to fit in the 3910? Even if they aren't Dell brand ones. I used a Segotep PSU to upgrade my Inspiron 3670 and it works just fine.

I just don't want to have to buy another GPU, since I just recently got mine. But I don't know if it will even fit in the tower.

You're missing the point. It's likely a customized PSU which has a custom 8-pin connector to the motherboard.  So you won't find any off-the-shelf PSU with the right connectors and voltages, and that assumes a different PSU will fit in that space inside the case. Look at the motherboard components image here.  The PSU is a long narrow rectangle. 

Suggest you read some of the threads about possible PSU upgrades in Inspiron 3910.  If a 460 W PSU from Dell is news, that should tell you other PSUs aren't going to work. So the Inspiron 3910 might not be a good choice if you want to use the RTX card you already have. 

@RoHe​ Okay, I think I understand. That's disappointing, but thank you for your help.

You're welcome. 

Maybe a DIY custom build would be the way to go.  Or look for a different pre-built model that comes with at least a 550 W PSU.

Don't know your budget, but you could get an XPS 8960 with only onboard Intel Graphics (no add-in video card) and 750W PSU for ~$700, base price and install your RTX 3060 card.  And there might be good deals for Black Friday and/or Internet Monday shopping...