How much should an 8 ft Red Tail Common Boa weigh? I'm going to weigh Roxy. She looks fine but somebody asked me and I have no concept of weight and measurements.

I'm not sure about weight, I would go by girth.

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~Christi
1.0 Red Ear Slider: Mikey
1.0 Het for Albino Red Tail Boa Constrictor: Kaa
0.0.1 Northern Blue Tongue Skink: Petri
1.0 American Staffordshire Terrier/Lab: Brutus
1.0 German Shepherd: Pax
1.0 Husband: Will
“Life is as dear to the mute creature as it is to a man. Just as one wants happiness and fears pain, just as one wants to live and not to die, so do other creatures.”——His Holiness The Dalai Lama

Probably a better indicator. So how wide should her widest part be in proportion to...her head?

I never weigh mine either. I just judge by the way the body feels.
As long as the body feels heavy and full I don't worry about it.
Boas are a full bodied snake but not as rotund looking as say a ball python.

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Merlin,
What's Life Without A Little Magic!

Posting a pic would help us answer better.

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~Christi
1.0 Red Ear Slider: Mikey
1.0 Het for Albino Red Tail Boa Constrictor: Kaa
0.0.1 Northern Blue Tongue Skink: Petri
1.0 American Staffordshire Terrier/Lab: Brutus
1.0 German Shepherd: Pax
1.0 Husband: Will
“Life is as dear to the mute creature as it is to a man. Just as one wants happiness and fears pain, just as one wants to live and not to die, so do other creatures.”——His Holiness The Dalai Lama

We weigh our snakes regularly after they defecate. It helps us keep an eye on their growth patterns and, in case of fasting periods, if they are losing or maintaining their weight. We can also see that with regular feedings if the weight is not going up much, it might be time to up the size of the food item.
I find it an important indicator of over-all health. As with any animal, individual weights will differ. Look at your snake carefully. Wrinkles or sagging skin would indicate the weight is too low -- can also indicate dehydration. If you see skin showing between the scales, your snake could be obese -- this is not a healthy condition. If he feels solid and muscular, is shedding regularly and eating well: he's probably OK.
But I would start weighing him regularly to develop a guideline of where he is and how he grows in the future.
Depending on how big he is, you can hold him and stand on a scale, then stand on the scale yourself alone.

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Andrea

Rhiannon is reaching 11ft now. She's always been skinny since I rescued her, which is odd looking when a snake is so long. However, her weight never got up to "normal" until just a couple months ago. When I took her to the vet to get her probed, he weighed her and she was around 21lbs. He said that she has her ideal weight, isn't obese, is all muscle, is the most gorgeous boa he's ever seen etc etc. (Now I'm just bragging. )

But when I heard 21lbs, I thought that was a little skinny.
Apparently it's not.
So going by girth, like previously stated, is best.

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The Zoo

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1.0 Hog Island Boa
0.1 Dumeril's Boa
2.0 Albino Burmese Pythons
3.3 Ball Pythons (2 normal, 2 spider, 2 pastel)
0.1 Blood Python
3.0 Corn Snakes
1.0 100% het albino Western Hognose
1.1 West African Gaboon Vipers
0.1 Rhinocerous Viper
0.1 Albino Monocled Cobra
0.1 Dusky Pygmy Rattlesnake
1.1 Vietnamese Blue Beauty Ratsnakes
1.0 Southern Copperhead

I apologize. I must not have stated my question well. I am not worried about her weight, it was just a question I was asked. And who better to get the answer from? You guys, of course. Her skin is not sagging and I know to weigh myself first. As ugly as it may be. She weighed in at a healthy 19 pounds and Thank you, especially, luxemburger_queen, for giving me an idea. I was just looking for a ballpark figure. I have pictures already posted and I actually still am on dial-up. So, new pics will come when I think I remotely have the patience for the downloading. I knew I could get the info from this site!! Thank you all!!