How many calories are in walnuts?
A 30 g (1 oz) handful of walnut halves is about 195 kcal. That is roughly 15 halves, so about 13 kcal each. Walnuts are the most calorie-dense nut on the shelf — two-thirds fat by weight — which is worth knowing before you add them to anything by the handful.
Per portion
| Portion | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|
| One half (about 2 g) | ~13 kcal | 0.3 g | 0.3 g | 1.3 g |
| 5 halves | ~65 kcal | 1.5 g | 1.5 g | 6.5 g |
| Handful, 30 g (about 15 halves) | ~195 kcal | 4.5 g | 4 g | 20 g |
| 100 g shelled (about 1 cup halves) | ~655 kcal | 15 g | 14 g | 65 g |
| 100 g in the shell | ~300 kcal | 7 g | 6 g | 30 g |
| 1 cup chopped (about 115 g) | ~755 kcal | 17 g | 16 g | 75 g |
| 1 tbsp walnut oil (14 g) | ~120 kcal | 0 g | 0 g | 14 g |
Carbohydrate figures include about 7 g of fibre per 100 g.
What changes the number
Shelling, more than anything on this list. Walnuts are only around 45% kernel by weight, so 100 g bought in the shell gives you roughly 45 g of edible nut and about 300 kcal. The same 100 g shelled is 655 kcal. No other variable on this page comes close to a factor of two.
Toasting. Dry-toasting in a pan drives off a little moisture, so toasted walnuts are marginally denser per gram — a few per cent, not worth tracking. Toasting in oil or butter is a different matter, and the fat the nut picks up can add 30–60 kcal per 30 g portion.
Candying and coating. Candied walnuts, maple walnuts and the glazed versions on salads run 500–600 kcal per 100 g. Counter-intuitively that is lower than plain walnuts, because sugar carries less energy per gram than fat — but the portion eaten is usually much larger.
Age, which changes flavour and not calories. Walnuts go rancid faster than most nuts, and a bitter, stale walnut has the same 655 kcal per 100 g as a fresh one. Taste is not a calorie signal.
Where it fits in a deficit
Walnuts give you the least protein per calorie of the common nuts — about 2.3 g per 100 kcal, half what peanuts manage — and they are the densest, so on pure deficit arithmetic they are the most expensive nut you can buy. A generous hand on a salad is 40 g and 260 kcal, which is more than the salad underneath it.
They are also satiating, chewy and genuinely useful in small amounts. The honest version: five to seven halves, 65–90 kcal, is enough to change the texture of a bowl of yoghurt or a salad without reshaping your calorie deficit around it. Scattering them is fine; snacking on them from the bag is how a 200 kcal habit becomes a 600 kcal one. Almonds give you more food for the same calories if volume is what you are after — see high-volume foods for why that matters.
About the omega-3, honestly
Omega-3 is the usual reason people eat walnuts, and the claim is real but narrower than it sounds. Walnuts are the richest common nut source of ALA, the plant form of omega-3: roughly 2.5 g in a 30 g handful, which exceeds most daily intake recommendations on its own.
What they do not contain is EPA or DHA, the long-chain forms found in oily fish. The body converts ALA to EPA and DHA at a low and variable rate — single-digit percentages for EPA, less again for DHA — so walnuts do not replace fish or an algae supplement. Excellent ALA source, poor EPA source; both are true at once.
None of this affects the calories. Thirty grams is 195 kcal whether you eat it for the fat profile or the taste, and if you are working to a target it costs the same either way.
Figures are typical values and vary by variety, size and preparation. General information, not medical advice.