What is the perfect amount of megapixels?

I know the more megapixels the better but I also know that if you have too many then most lowlight pictures would come out bad. I was close to buying the Nikon d3200 since it's very cheap for that amount of megapixels but then I read a review about the result of it's lowlight pictures. So what I'm asking is there a sort of inbetween amount that would be good for well-lit and low-lit pictures?

You are spot on - more megapixels gives you a higher linear resolution but as you make the pixels smaller, they perform more badly in low light. An extra complication is that newer sensors are better than older sensors, even if they technically ought to be "worse".

If you are worried that the D3200 has too many pixels, get the D3100.It has 14 megapixels which is plenty for anything.

Pixel density matters more than the number of pixels, or at least it used to. DP Review stopped listing the pixel density about a year ago as "no longer an indication of image quality".

In the last few years the goalposts have moved dramatically, the new Exmor R sensor from Sony and it's derivatives which are being released currently on an almost weekly basis has changed things.

As an example here is an image from my Pentax Q, a camera with a tiny (1/2.3 Inch) sensor with 12.4Mp crammed onto it, results should be terrible especially as the image was taken in low light with an ISO of 800, even then with the aperture a wide f1.9 the shutter speed still had to be 1/5th of a second, but judge for your self

Jpeg strait from camera

If you go to the trouble of processing yourself from the Raw file, you can get this. No noise software was used, the noise level is strait out of the camera, i.e. Not much.

An image of this quality would have been impossible just a few years ago, even APS sized sensors would have struggled in this lighting.

The problem now is with the pixels being so small you can't use small apertures as the diffraction they cause at this tiny resolution exceeds the resolution of the light itself and image quality visibly gets worse!

There's the promise of even more to come from sensors.

There's no perfect amount of megapixels. It's not even the quantity but the quality of the pixels. The D3200 is a fantastic camera and will be great for you. Even at the pro level, you can't just say a camera is better because it has more megapixels.

You know wrong.

http://keerok-photography.blogspot.com/2012/09/megapixels-is-only-about-picture-size.html

It has nothing to do with low light or picture quality for that matter. What's good for well-lit and low-lit pictures is a good understanding of the basic principles of photography.

http://keerok-photography.blogspot.com/2012/10/learn-photography.html