How heavy is a giant sandworm?

This is our calculation, not an official number. Frank Herbert never gives a sandworm’s weight, and neither do the 1984 or 2021 and 2024 films. What the novel does give is length: the Shai-Hulud entry in the glossary of Dune (1965) says worms of more than 400 m (1,312 ft) have been recorded by reliable witnesses, and that even larger ones probably exist. A width of 40 m (131 ft) is the figure usually quoted alongside it, though it is not clearly stated in the novel.

A worm is close to a cylinder, so the volume is the area of the circle times the length. A 40 m wide worm has a radius of 20 m, so its cross-section is π × 20 × 20, about 1,257 m². Multiply by 400 m and you get about 502,700 m³. Animal flesh is roughly as dense as water, 1,000 kg per cubic meter, which gives about 502,700 tonnes. We round that to 500,000 tonnes, or about 1.1 billion lb.

The real figure could be lower, since a worm tapers toward the tail, or higher, since Herbert’s worms are covered in hard ring segments and have a mouthful of crystal teeth. Either way, it is a ballpark.

Herbert’s worms vary a lot. When Paul first sees one up close, its mouth is described as some 80 m across, which is hard to fit on a 40 m body. A worm 400 m long and 80 m wide would have four times the cross-section, so about 2 million tonnes. The worm Paul summons for his first ride appeared to be “more than half a league long”, roughly 2.4 km (1.5 miles). Six times longer at the same shape means 6 × 6 × 6 = 216 times heavier, so over 100 million tonnes.

At the other end, Appendix I of the novel says young worms come out of the sandtrout stage about 3 m long, and that a stunted form only reaches about 9 m. At the same proportions, those would weigh about 210 kg and 5.7 tonnes.

David Lynch’s 1984 film used models built by Carlo Rambaldi, the designer of E.T. According to Monster Legacy, the fully articulated worms were 22 ft long and 3 ft wide, about 7 times longer than wide. Scaled up to 400 m, a worm of that shape would be about 55 m across and weigh around 935,000 tonnes.

Denis Villeneuve’s films never give a length either. Villeneuve said he wanted the worm to feel like a prehistoric creature, with a baleen-like filter in its mouth for feeding on the sand. Articles often describe the film worms as almost half a kilometer long and 40 to 50 m wide, but we could not find that figure in any statement from the studio or the effects team. DNEG, which did the visual effects, says the sand simulations for the worm wakes were hundreds of meters long, and that the spice harvester in Dune: Part Two is 120 m tall. For Paul’s ride, the crew built a 90 ft by 24 ft piece of worm back on set.

Not on Earth. A University of Utah biology article points out that a blue whale is about 34 m long and 380,000 lb (172 tonnes), and a 400 m sandworm is ten times that length. Our 500,000 tonnes is about 2,900 blue whales. Scientists quoted by Popular Science say real worms breathe through their skin, which would not supply enough oxygen to something so large, and that a worm this size would likely be crushed under its own weight.