Yeah, this is probably way too in the weeds, but I can’t seem to find a good answer – googling gives some numbers for calories per oz, or per tbsp, or per cup, and then some different numbers on seeds per cup or whatnot, but they aren’t consistent, and it doesn’t say whether it’s shelled or unshelled for the volume and weight measurements.
Any ideas? I would think this would be easy to figure out, but I’m failing so far…
Sunflower seeds come in at least two varieties, Jumbo and regular. Which one are interested in and how accurate do you really need to be?
I would buy a pack and look at the calories per serving, and the number of seeds per serving, and do some simple math.
The packs I have available don’t say seeds per serving, they use volume.
… if they give you calories per volume, can’t you measure out that volume, count the seeds, then divide the calories by that number of seeds?
I happen to have two brands of salted roasted dehulled sunflower seeds with nutrient labels and an inexpensive electronic scale with claimed precision of 10 milligrams. I weighed 20 seeds of each brand, excluding obviously broken ones.
Brand 1) 1.24 grams per 20 seeds, 180 kcal per 30 gram serving, hence 0.37 kcal per seed
Brand 2) 0.89 grams per 20 seeds, 190 kcal per 30 gram serving, hence 0.28 kcal per seed
I also have bulk dehulled raw (not roasted, not salted) sunflower seeds, but no nutrient information for them. They weigh 1.45 grams per 20 seeds.
Now that’s SCIENCE!
Curious about why you want to know the calories in each seed?
Wow, thanks so much! I’ll average this out to 1/3rd calorie per seed.
Calorie counting – I recently started snacking on sunflower seeds (since it takes a long time to eat them and therefore it’s hard to eat too much). I usually eat about 20-30 seeds a few times per day, and I couldn’t find an estimate as to how many calories this would be.
You may be burning more calories than that to get them out of the package, into your mouth, chew them, and digest them 
Forget the calories, worry about the sodium content if you’re eating lots of salted seeds.
Sunflower seeds have nothing on Pumpkin seeds in terms of sodium, so thats at least a better choice, any of the spicier flavors of sunflower seeds always have more sodium.
The whole bag only has about 20% of a day’s sodium, and it takes me at least a week to eat a whole bag, so I’m not too worried about sodium from the sunflower seeds.