Primaris Space Marines -- Proportions comparison

Maybe you are as excited as me about the new Primaris Space Marines that GW released a short while ago? When I see them, I see correctly scaled Space Marines which are finally trully giants compared to Guards Men, as it should be! You were also bothered by the fact that many Chaos Space Marines where shorter than a simple Guards Men?! Well, these times are over fortunately. Even the new Death Guard which obviously wear old Marks of Power Armour  (mainly Mark II and III)  are now as large as the new Primaris!

When I now see an old Space Marine miniature, I can not help it, I just think that the legs are to tiny and the head way to big, they look like weird freak dwarfs. I can not imagine painting anymore of these abominations. For me there is no way back! Which is of course ironic as I have almost completed my Space Marine metal miniature collection with all the "previously awesome" Space Marine models from the 2000s. Do not get me wrong, I still love the character of all these fantastic miniatures but  all Marines should be "true-scale", i.e. Primaris size.

I know a lot of you already made great efforts to convert normal Astartes to True Scale, e.g., here  and here, and of course I was immediately wondering whether it would be possible to convert the old models to the Primaris size. The conversion is probably very complex because according to GW's own words only the heads and shoulder pads are still the same.  But how much does every body part be enlarged?

In order to find out, I took some Primaris Parts from the Dark Imperium set and from the latest tactical Space Marine box and took some detailed comparison shots. Let's go through them from the bottom to the top:


1. Lower body (legs, boots):

The lower body of the old Space Marines measures from bottom of the boot to just below the belt measures 1.8cm if we ignore the slightly bended knee, while for the new Primaris, we have 2.2cm, so ~22% higher. In more detail:

• Boots: The new boot is more massive than the old one in every aspect by ~10%, it is longer (1.1cm vs. 1.0cm), wider and higher, even ignoring the additional new armour plates.
• Lower leg: similar to the boot, the new lower leg is just more massive in every way as well, more like an old Terminator leg (which is why most true-scale converters used those). The old lower leg measures roughly 0.8cm to the knee while the new one is 1cm. When the older knee armour plate center was on ~1.1cm, the new one is on ~1.4cm, so this is where the Primaris Marine gains most of its additional height from! 
• Thighs: The Primaris thighs on the other hand are not longer than those of an old school Marine! Just the armour is thicker, again more like that of an old Terminator suit.

1. Upper body (torso):

The above pics show that the upper body grew quite a bit from normal to Primaris Marine. The old upper body from belt to shoulders measures roughly 1.0cm, while the Primaris is 1.2-1.3cm, so ~25% growth,  matching the increase, we have in the lower body. Both the belly and the breast are longer, while the width is only slightly extended. In addition, the Primaris torso has a higher depth. So bad news: it is going to be very difficult to change an old upper body to Primaris proportions, unfortunately!
From the back it looks a bit better on first glance but when you look closer you see of course that the same that applies to the front also applies to the back...

3. Arms:

The above image shows on old Marine arm on top of a Primaris arm, followed by another old arm.
From it, it seems that the arms of the Primaris Marines are very similar to those of the old Marines. The total length and also the segment proportions are the same. the hands are the same as well. So good news: no conversion needed here! Old and new arms should be completely interchangeable.




 4. Backpack:

As you can see in the above pictures, the backpack containing the power plant did NOT grow by ~20% as the rest of the Primaris. Instead, the Primaris backpack is basically the same as from the previous marks with just an additional thin layer of armour added to the top part and the exhaust jets, as well as the circular plate in the center. So again good news:  no conversion needed here as well but interchangeability!

5. Bolter:

While the bolter is not part of the armour, some might consider it an part of the Marine, so just out of curiosity, let's compare the old Godwyn pattern Bolter with the Mk II Cawl Pattern Bolt Rifle.  The above pics show that both are very similar in fact with the striking difference that the Cawl Pattern is longer because of this added "segment" in front of the lower grip, namely 2.1cm compared to 1.7cm. Otherwise all dimensions are basically the same.


Summary:
So in conclusion, we see that most of the difference between the old Marines and the new Primaris size lies in the lower legs and the whole torso, while both lower and upper body are more massive, excluding the arms. The arms, heads, backpacks and weapons are so similar that they are basically interchangeable.
Of course, in particular the huge differences in the upper body mean big trouble for any attempt to convert old Marine miniatures to the new size and true scale. I personally, I am not sure what to make out of this yet. While I love, many of the old miniatures, in particular the characters and metal miniatures, conversion is going to be challenging to impossible. Maybe it will be easier to take the bodies of Primaries and convert them to be similar to the old models with lots of Green Stuff... ;-)