As Seen On TV
The Zentradi and Meltrandi are shown somewhat inconsistently throughout most of the original Super Dimension Fortress Macross series (released in 1982). When shown along side humans, the Zentradi are drawn somewhat larger than their actual dimensions owing to a dramatic effect. Although the Zentradi are depicted as mostly correct for a giant size being of human-like proportions, the Zentradi hand appears oversized when a human is held within the grasp of their palm (assuming a 10 meter tall Zentradi). However, the proportional differences between a Zentradi and a human can be understood as dramatic effect and for the most part, the larger Zentradi (Britai, Bodolzaa, Kamjin) are the ones shown holding humans.
The animators appear to take creative license when Maximillian Jenius incapacitates a Zentradi and utilizes his clothes to disguise his VF-1A Valkyrie Battroid (12.68 meters tall). Fans may rationalize this as Max stumbling upon another commander-type Zentradi or just a regular Zentradi that happens to be tall (like Kamjin, who was 11.85m tall).
However, the original SDF Macross series animators also took creative license with the Zentradi on other occasions, especially episodes animated by the cheaper animation studio STAR PRO (a sub-contractor of Anime Friend). Zentradi were sometimes mistakenly drawn as equal in size to a VF-1 Valkyrie Battroid, a mecha which is 12.68 meters tall. This has given many fans of the original series the mistaken impression the VF-1 Valkyries were designed to be the same height as the average Zentradi. However honest a mistake this may be, these sequences remain the primary source of confusion over the proper size of the Zentradi.
Kamjin, The Unified Theory Killer
The Zentradi villain Kamjin from the original Super Dimension Fortress Macross series (released in 1982) is one of the first problems to arise when properly measuring the Zentradi. Official statistics state Kamjin is 11.85 meters tall but Kamjin is also shown piloting a Glaug, which is only 16.55 meters in height. If Kamjin is nearly 12 meters tall, he is clearly too large to fit inside the cockpit of the Glaug. At best, the Glaug might accomodate a 10 meter tall Zentradi. In this case we can assume that either Kamjin's height is wrong, the size of the Glaug is wrong or that both sizes are correct and we are meant to ignore the problem.
The Kurious Kase of Klan Klang
The Macross Frontier series (released in 2008) introduced the Meltrandi pilot character Klan Klang. Many fans have commented on her apparent height discrepancy as a full sized Meltran. Klan's height, particularly in a sequence where she is standing next to Mikhail's VF-25G, is far greater than an average Meltrandi female. Most likely, this discrepancy is creative license on the part of the animators and director. The scene in question was designed to be a personal character development sequence between Klan and Mikhail, a sequence which works much better if Klan appears only a little shorter than her mechanical counterpart. Many fans also note that in this scene Mikhail's VF-25G Battroid emotes with non-verbal gestures as though the machine were human. Clearly the point of the sequence is to communicate emotion to the audience, while scale and some suspension of disbelief is sacrificed to make the sequence work better for the intended purpose.
Nonetheless, to satisfy the nitpickers, the sequence can be examined to determine the height of Klan Klang. Official literature states that VF-25G is 15.59 meters tall in Battroid mode (cannons included). Klan appears to be no less than a meter or two shorter than Mikhail's VF-25G Battroid. Indeed, Klan's head seems to indicate she is just below the shoulder of the VF-25 Battroid and she is tall enough to strike the VF-25G head unit with her outstretched arm. If we were to accept the above sequence as accurate for scale purposes, Klan Klang would be roughly 11-12 meters tall as a full size Meltran. If Klan is really 11-12 meters tall, she is far larger than than an average Meltran such as Milia, who herself stands 8.55 meters tall when full size. However, Klan is still shorter than Britai's 13.54 meter height and she would be nearly the same size as Kamjin, who is 11.85 meters tall. To reconcile this discrepancy, fans could assume that Klan is either descended from the larger commander-type Meltrandi or Klan is naturally an exceptionally tall example of her race.
Unfortunately, declaring Klan Klang as 11-12 meters tall creates a problem similar to Kamjin whereby Klan is too large to occupy her Queadluun-Rhea battle suit (which is 16.85 meters tall). To avoid such a problem it is perhaps wisest to simply accept Klan as an 8-10 meter tall Meltran so she can properly occupy her Queadluun-Rhea. We would then dismiss Klan's brief increase in size next to the VF-25G as creative license on behalf of the animators.
Do You Remember Size?
Some more skeptical fans have pointed out that while the official size figures printed in official Macross books are interesting, they cannot override what appears as canon in the anime productions. Even if the examples of poor scale are the result of budget problems (such as the poorly animated episodes drawn by STAR PRO) or creative license, some fans argue that canon Macross is ultimately the animation itself. However, there are significant, plot-relevant and canon benchmarks (the Zentradi soldier emerges from his Reguld in SDFM episode 2, Britai vs. Hikaru's VF-1J in SDFM episode 11, etc) as well as accurate scaling in the film The Super Dimension Fortress Macross The Movie: Do You Remember Love?. The film version of the original Macross series features several key sequences that confirm the correct Zentradi and Meltrandi sizes. When Roy Focker is captured in his VF-1S Strike Valkyrie, his Battroid is approached by several Zentradi soldiers. In this sequence, the Zentradi are shown as several meters shorter than the VF-1S Battroid. Also, in Roy's final Battle against Kamjin, the full sized Zentradi is shown as noticeably smaller than the seated VF-1S Battroid. These depictions are consistent with a 12.68 meter tall VF-1S Battroid compared to a roughly 9-11 meter tall Zentradi.
It is also worth noting that The Gold Book features a size comparison chart of Zentradi Soldiers, Britai and Exedol. This chart seems to show Britai at a much smaller height, perhaps the 11.38 meters mentioned in This Is Animation #11. Since a size chart in that very issue of TIA #11 depicts Britai at his regular 13.54 meter height, we can assume the smaller size chart in The Gold Book is not indicative of the proper Zentradi heights.