# How much does Commander Data weigh?

I'm referring to his "typical" weight, as in how much he weighs during his day-to-day activities aboard the Enterprise (minus the pipe).

• The pipe lends gravitas, not gravity. Commented Aug 25, 2019 at 6:43
• @Valorum: physics nerd nitpick: the pipe, having mass, lends both gravitas and gravity.
– 0xdd
Commented Aug 26, 2019 at 15:15
• @0xdd - Unless it has built-in anti-gravity plating. Which is perfectly possible in the world of Trek Commented Aug 26, 2019 at 15:43
• @0xdd - Engineering pitpick: it doesn't add gravity (to all significant intents and purposes anyway), it adds weight. Commented Aug 27, 2019 at 10:42
• @AndyT: Physics nitpick v2: Actually it adds mass, which results in an increased measure of weight in a gravitational field Commented Aug 27, 2019 at 11:57

## 3 Answers

Approximately 100 kg (= 220 lbs.) according to his 'mother'.

DATA: My -- childhood?

JULIANA: (laughing) That's what I called it. You were like a baby at first -- a hundred kilogram baby, but still...

TNG: Inheritance

This tallies with his official fact file on the StarTrek.com website, although this is likely a case of the tail (TNG: Inheritance) wagging the dog.

Bio-engineering Review: Joint Report of CMO Beverly Crusher, M.D. and Chief Engineer Geordi La Forge

Data, who weighs 100 kg., carries a concealed master on/off switch centered just below his right shoulder blade. This switch is known only to the senior staff of the Enterprise: commander, first officer, chief engineer, chief medical officer and ship's counselor.

Purely for reference, the pipe in question appears to be a Pioneer Pipe Co. "Calabash" pipe (with a replaceable cap gourd). They weigh approximately 82 grams.

• @PatrickTrentin - Ah well, we see him with a whole pile of spare body parts in TNG: Datalore and we know he swapped bodies with a prototype Soong-type android in Nemesis. It's unlikely that these parts weigh dramatically more or less than his original parts. Commented Aug 25, 2019 at 20:27
• @PatrickTrentin It's not specified by the sentence, but "You were like a baby" here doesn't have to mean "You looked like a baby". It could mean "You were unable to understand anything or do anything, like a baby". Commented Aug 26, 2019 at 3:50
• I think the '100kg' remark was a generalisation just to illustrate that he was considerably heavier than a human baby. Much as we may say somthing heavy 'weighs a ton', its not to be taken literally. Commented Aug 26, 2019 at 4:45
• @PeterWard - And while that's probably true (that it's a generalisation), the ST website says that it's exactly accurate. Commented Aug 26, 2019 at 6:18
• @jpaugh - There are dozens of examples of this here. For example, from TNG Loud as a Whisper "PICARD: This is Captain Jean Luc Picard, commander of the Federation starship USS Enterprise. If you continue to violate the cease fire, I will abort this mission." Commented Jun 1, 2020 at 19:10

I'll expand on the point I think Don is making.

Humans are, on average, slightly less dense than freshwater; about 1-2% less. 997kg/m^3 vs 985.

Data not only sinks in freshwater, but he's dense enough to comfortably walk on the bottom (Insurrection). Since Data is the same volume as a human he must weigh more to be more dense.

At 180cm (Brent Spiner's height) a fit human male would be about 75 kg. An extra 2 kg, with no increase in volume, would be enough to make him just more dense than water. To be dense enough to comfortably walk on the bottom he'd need even more weight. How much more I can't say. An enterprising person could strap on weights and try replicating the scene from Insurrection. 😁

100 kg would make Data about 33% more dense than water. That's likely plenty. The physics checks out there.

What about water leaking in and displacing air? In Insurrection we see him walk straight into the water, so he was already significantly more dense regardless of leaks. We don't see any bubbles which would be evidence of water displacing internal air pockets.

While in Descent it's mentioned he's not waterproof, there's evidence that was fixed. Data walks into the water non-nonchalant and there's no mention of ill-effect later in the film. Despite being cut off from a repair facility for Data, Picard seems completely at ease when Data submerges himself. And finally, Data demonstrates he's a flotation device; he wouldn't be a very good flotation device if he leaked.

UPDATE: Peter Cooper Jr. observed that in Insurrection we see Data both comfortably walking on the bottom of a lake and also acting as a flotation device bobbing halfway out of the water in that same lake.

At 100 kg, what does it take to do both?

At 180 cm (Brent Spiner's height) fit human is roughly 75-80 kg and about 80 L of volume. I'll use 80kg for round numbers. Data is the same build as a fit human, thus the same volume, but weighs 20 kg more. That makes him 25% more dense than a human. Humans are only slightly more dense than water. Data is significantly more dense.

In order to bob halfway out of the water, assuming there's no handwavium involved, Data must go from 25% more dense than water to about 50% less dense. He can do that by increasing volume or shedding "ballast". This ballast cannot be water as that would only take him towards neutral buoyancy. Indeed, we hear a balloon inflating implying he's increasing volume. Assuming it's full of some very diffuse gas such as helium, how big does that balloon have to be?

Data has to go from 1250 kg/m^3 to 500 kg/m^3. He needs to increase his volume by 150%. At 80 L this is an extra 120 L or almost a bathtub's worth of extra volume.

• We've already established that he's not waterproof. Commented Aug 26, 2019 at 17:04
• @Valorum Yes, though that might have changed by Insurrection. At the end I cover why waterproofing is not relevant given what we see in Insurrection. If water leaking in was significant he wouldn't walk straight into the water until fully submerged. He'd float and flounder a bit and slowly sink as water slowly leaked in. Commented Aug 26, 2019 at 18:03
• This assumes the water "leaked in" slowly. What if his bioplast skin is basically an open mesh when it comes to water? Commented Aug 26, 2019 at 18:55
• @Valorum Then he'd better not go out in the rain. Yes, for all we know he can dynamicly adjust his bouancy by replacing microscopic air pockets with water, but there's no canon for that. Commented Aug 26, 2019 at 22:40
• @Schwern: I thought that when he says he's a flotation device in Insurrection that he's floating in the water, though it has been a while since I've seen it so I may be misremembering.
– user22502
Commented Aug 27, 2019 at 18:10

Given Data's size and a density that causes him to immediately sink he must be significantly north of 100 kilos.

• This is an interesting point, but a bit thin for an answer. Can you come up with a number for what his weight would be if he were a human, as a point of comparison? This would also be better if you could provide a reference for a scene or scenes where he sinks. Commented Aug 26, 2019 at 1:34
• Interestingly, the only way he could sink and still weigh 100kg would be if he's not watertight. Which seems unlikely. Commented Aug 26, 2019 at 4:02
• @ApproachingDarknessFish - In "Descent, Part 2" (TNG 7x01), Geordi and Data talk about Data's unsuccessful attempt at swimming in Devala Lake: "It took almost two weeks to get the water out of [Data's] servos." Commented Aug 26, 2019 at 4:41
• Human beings as they are just barely float. He wouldn't have to be a whole lot denser that a typical person to sink. Commented Aug 26, 2019 at 4:41
• Add to that the fact that Data can, without being troubled in any way, hold an anvil weighting approx. 50 kilograms with his arm stretched out. Which, apart from his (obviously present) super strength, requires significant weight in order not to topple, regardless of how strong his arms may be. Commented Aug 26, 2019 at 8:07