14 million.

This may be a bit confusing so I'll count from day of release so in my opinion sales of the Switch from beginning of March 2018 to beginning of March 2019 should be something around 10 - 12 million units.
So adding the 15 million units sold during the first year (March 2017 to March 2018) by March 2019 the total sales should be of 25 to 27 million units.

What makes you think that?

New Leaf which released in 2012/2013 sold the same amount as Wild World which released in 2005 and is the best selling 3DS game in Japan at over 5 million and the 7th best selling 3DS game globally at 11.7 million.

Even the spinoff title released in 2015 sold close to 4 million.

Would you mind going into detail why you think sales will be so low?

They are forcasting to ship 20 million from April 1, 2018 to March 31, 2019. Sure, its possible that they miss their forcast but by ~8 million? I doubt thats happening.

For the calendar year 2018, with Pokémon + a price cut and/or some bundles for the holidays, about 18 millions seems attainable.

I am thinking about 18-20 million. It really depends on what the lineup is for the 2nd half of 2018. E3 will make me sure what the sales will be.

Edit: I just realized that posted here already and I had the same prediction. At least I am consistent.  

I think this game in general fares better as handheld game than as a full blown Console game. Which is kind of what we expect from Switch nowadays. I could be wrong though.

From all the people I know who want a Switch I heard Zelda, Smash, Mario Kart, Mario Oddesey, Pokemon and even Metroid (before both where announced) as main reasons to buy a Switch. Yet I never heard animal crossing as main reason. Perhaps Japan will love animal crossing to death.

As I said I could be wrong but I simply can't see the hype for a new animal crossing outside of fora like these. Anyway my estimate is somewhere between 17.5 and 18.5 million, pretty much equal to Playstation 4 sales which I estimate somewhere between 18.5 million and 19.5 million.

First if they sell 12 million Switches in their second year it's not what I would call "low sales".

And to answer your question, they sold 15 million units their first year because there was Zelda BOTW that pushed the sales, I mean the vast majority of people who bought a Switch the first year did so for Zelda, the attach rate was super high, very few Switches sold with no intention of playing Zelda. Then Mario Odyssey came along and gave a push too.

But the second year you will not have such names to push sales. There certainly will be new Zelda and Mario games but not this year obviously.

Of course you can say there are other games expected this year but I don't think they will have the same impact as the first party mega names like the two I talked about. Last year nobody had a Switch so if you wanted to play Zelda you had to buy one. This year 15 million people already have a Switch so the big titles of this year will be shared between people who already own a Switch and those who don't and that means the impact on sales should not be the same as last year.

Now the Switch could very well end up selling much more than I predict but that would mean there are masses of new comers that would care to get a Switch for games that are not the big ones from Nintendo. Of course I don't know the exact schedule of releases from Nintendo so there may be big games I am not thinking of. I think I heard that there was a big Pokemon game coming and that game could seriously push sales but other than that one which big names would?  So the rest would be up to third party games or if more and more games of all genres come to the Switch, the variety could push sales up too I suppose.

The bottom line is I'm simply making a prediction without any certainty, it's just my humble opinion and I admit I don't have all the info to make a scientific prediction. Let's just say if the Switch sells 12 millions units this year, It will be a very decent figure, if it sells significantly more then I'll be officially impressed

Yes Animal Crossing performs much better on handhelds, good thing Switch acts as a handheld

Well were the people you know hyped for Animal Crossing on DS or 3DS? AC is huge in Japan and in the West it is primarily played by kids & females. So im not sure if your friends are a good indication of how well a new one would do.

Overall i agree, i think Switch will do ~18 million.

18M+ this year, but 20M+ for the financial year. The slow 1st half of 2018 in terms of exclusives and other consoles sales-pushing games is the reason for the difference.