Walnut Calories & Nutrition Calculator

English walnuts contain 9.08g alpha-linolenic acid (ALA, 18:3 n-3) per 100g — the highest ALA concentration among all tree nuts and the second-highest among all common nuts and seeds (after flaxseed at 22.8g). Pecans have 0.99g, cashews 0.06g, almonds 0.003g. No other tree nut approaches walnuts for plant-based omega-3 content ^[1][2].

Per 1-ounce serving (28g, ~14 halves): 2.54g ALA — well exceeding the 1.1–1.6g/day adequate intake set by the Institute of Medicine. Even 7 walnut halves (14g) deliver 1.27g ALA, meeting the minimum adequate intake from half an ounce. The body converts a small fraction (2–10%) of ALA to EPA and DHA ^[1][3].

Black walnuts have a different fatty acid profile with substantially less ALA (~2.6g/100g) but higher protein (24.1g vs. 15.2g). The ALA advantage is specific to English/Persian walnuts (Juglans regia). For omega-3 food journaling, the species distinction matters: English walnuts deliver 3.5x more ALA per gram than black walnuts.

English walnuts contain 47.17g polyunsaturated fat per 100g — 72.3% of total fat — the highest PUFA proportion among all common nuts. Most other nuts are monounsaturated-dominant: almonds at 63% MUFA, cashews at 61% MUFA, hazelnuts at 79% MUFA. Walnuts are the exception — they are overwhelmingly polyunsaturated ^[1][2].

The PUFA is split between linoleic acid (38.09g, omega-6) and ALA (9.08g, omega-3), giving a 4.2:1 omega-6 to omega-3 ratio — substantially lower than sunflower seeds (~330:1) or almonds (~4,100:1). Monounsaturated fat is only 8.93g (14%), and saturated fat 6.13g (9.4%) ^[1][3].

Per 1-ounce serving (28g): 13.2g PUFA (10.7g linoleic + 2.54g ALA), 2.5g MUFA, 1.7g saturated. For food journaling, walnuts' fat profile is compositionally distinct from every other common nut — logging total fat alone misses this unique PUFA dominance.

English walnuts provide 3.41mg manganese per 100g — 148% of the daily value. Among nuts, pine nuts lead at 8.80mg, pecans at 4.50mg, then walnuts. Almonds have 2.18mg, peanuts 1.93mg, and cashews 1.66mg. Black walnuts have even more manganese at 3.90mg (170% DV) ^[1][2].

Per 1-ounce serving (28g): 0.95mg manganese (41% DV) — nearly half the daily requirement from a single ounce of nuts. Combined with copper (1.59mg/100g, 177% DV — not in the standard 25-field schema but noteworthy), walnuts are a concentrated source of trace minerals ^[1].

Manganese content is well-preserved during light toasting and soaking. For food journaling, both raw and toasted walnuts provide comparable manganese. Black walnuts deliver about 14% more manganese per gram than English walnuts — a modest advantage if manganese tracking is a priority.

The two commonly available walnut species have dramatically different nutritional profiles. English walnuts (Juglans regia): 654 kcal, 15.2g protein, 65.2g fat, 9.08g ALA. Black walnuts (Juglans nigra): 618 kcal, 24.1g protein, 59.0g fat, ~2.6g ALA. Black walnuts have 58% more protein but only 29% of the ALA ^[1][2].

Other differences: black walnuts have more selenium (17.0 vs. 4.9mcg), more magnesium (201 vs. 158mg), more phosphorus (513 vs. 346mg), but substantially less folate (31 vs. 98mcg). The flavor also differs — black walnuts are bolder and more astringent, while English walnuts are milder and more widely available ^[1][4].

For food journaling, selecting the correct species matters. English walnuts (the standard grocery store variety worldwide) should be the default. Black walnuts are regionally available in North America and specialty stores. If your journal logs 'walnuts' without specification, English walnut values are the standard assumption.

At 654 kcal per 100g, English walnuts are among the most calorie-dense common foods — second only to macadamia (718 kcal) and pecans (691 kcal) among nuts. The high calorie density comes from 65.2g fat per 100g (the third-highest among common nuts). The standard 1-ounce serving (28g, ~14 halves) provides 183 kcal ^[1].

A single walnut half weighs approximately 4g and provides 26 kcal, 0.6g protein, 2.6g fat (including 0.36g ALA). Counting by halves is practical: 7 halves = 91 kcal, 14 halves = 183 kcal, 28 halves = 366 kcal. For broken pieces or chopped walnuts, weighing is more accurate — 1/4 cup chopped ≈ 30g = 196 kcal ^[1][3].

Soaked walnuts (a common Indian breakfast practice) have the same nutritional content as raw — soaking adds water weight but doesn't add or remove nutrients. If logging by weight after soaking, the per-gram calorie count appears lower because water dilutes the density. Use the pre-soak weight for accurate logging.