What's the surface area/ size of the planets in No Man's Sky? Are they different sizes?

Solution 1:

There was a video here which found that it took 12 hours to walk half way across a planet, therefore it would be one day to travel the circumference.

So based on an average walking speed of 3.1 mph, it would have a 74.4 mile circumference with a 23.68 mile diameter. That's 119.04KM and 37.89 KM.

The planets do appear different sizes, but are all within a similar range.

Solution 2:

They are known to be varied in size, they are not all the same size but they are also not all different sizes and you can actually notice this in the game itself. For example you could be using the pulse engine and it says there are 10 seconds until you arrive to that planet but it still looks really far away, this is because it will be classed as one of the smaller planets in no mans sky, but you can also get ones that could take minutes to arrive there but they look the same size as the one that takes you 10 seconds... This means that it will be a planet of a much larger scale. I haven't yet found any sources that show the exact surface area variety.