Let's just say;

Switch: 21M
PS4: 9.5M
XBO: 2.5M
---
PS5: 4.5M
XBS: 3.5M

I’m going to guesstimate the following:
Switch: 21.16M
PS4: 10.12M
XBO: 2.72M

The above are literally based on nothing but thin air lol
---
PS5: 4.9M
XBS: 3.5M

I honestly think that PS5/XBS will sell what’s shipped basically, they each have there own respective fan base that will buy them no matter what, same as Nintendo does. Like day one I’ll be getting a PS5, just because I can.

The PS3 sold 8.25m in 2013, so a prediction less then that would be silly.

Switch - 21.5m
PS4 - 10m
XBO - 2.5m

PS5 - 4.5m
XBX - 2.8m

I think people underestimate next gen consoles. PS4 was sold out everywhere, Sony underestimated the demand by a lot, this time they'll be ready for a huge launch. Not only that, but also PS5 will come to Japan this year (PS4 released in Japan in February 2014). Now you may say "But PS5 won't be as successfull in Japan" yes but it'll still sell at least 500K at worst, which is still a good advantage over PS4.

I'll be very surprised if PS5 sell less than 5 million this year, even at 500$.

And if the rumor of Series X having 2 SKUs (one at a very accessible price) are true, it'll also sell way more than XB1 3m in 2013 those 2 SKUs combined.

I smell Vita LTD number for PS5 in Japan and next year is going to repeat the year of 2011 3ds(Switch) vs PSV(PS5)

Still a bit early since we don't know if we get multiple XBox series at launch. If Microsoft only sells that highend model they won't have that high sales. If PS5 costs 500 $ the sales also won't be as high as PS4.

Switch: 21M
PS4: 8M
XBO: 4M

PS5: 4M
SeXBox: 3M

Just so you know, PS3 sold 8.25m in 2013... It would be strange for the PS4 to suddenly perform worse than the PS3 launch aligned.

PS4 sales are trending down quicker than PS3 but 8m is pretty extreme.

Year 5

PS3-up 6%

PS4-down 10%

Year 6

PS3-down 15%

PS4-down 20%

Year 7

PS3-down 30%

PS4-down ???

Gonna make a slight change to my predictions:

Switch - 22.5m
PS4 - 9m
XBO - 2.5m

PS5 - 4.5m
XBX - 2.8m

Switch 24m > All other consoles combined.