Macadamia nuts

One US cup of macadamia nuts weighs between 134 and 149 grams, depending on how the cup is filled and which source measured it. That range is the answer; a single number would not be. Every figure behind it is below, with the method each source used.

Also called whole macadamia nuts, macadamia kernels, raw macadamia nuts, macadamias.

Two sources 11.19% apart, over the 10% milled tolerance, so this entry publishes the range rather than a single figure. USDA FoodData Central publishes Nuts, macadamia nuts, raw (SR Legacy) at 1 cup, whole or halves = 134 g, implying a density of 0.5664 g/mL. King Arthur's Ingredient Weight Chart lists 'Macadamia nuts (whole)' at 1 cup = 149 g, implying 0.6298 g/mL. The USDA cup portion is confirmed by proportional consistency across 0.5, 1, 1.5 and 2 cup entries, all dividing to the same 134 g/cup figure.

The likely reason for the disagreement is a difference in what was actually measured. USDA's own notation is 'whole or halves' — macadamia kernels naturally split at their internal cleavage axis when shelled, so a cup of 'whole or halves' contains a mix of intact spheres and split half-domes. Half-domes pack much denser than intact spheres because their flat cleavage face allows flat-to-flat contact, the same effect that puts peanuts at 146 g per cup despite individual kernels being roughly comparable in intrinsic density. If USDA's sample skewed toward whole intact kernels and King Arthur's toward halves and broken pieces, an 11 to 15 percent cup-mass gap is exactly what would appear. Neither source documents its filling method, so this remains a hypothesis rather than a confirmed cause.

Macadamia is also unusually variable across cultivars. Hawaiian Beaumont, Australian Own Choice and South African A38 differ measurably in kernel diameter, and the industry does not standardize which cultivars appear in generic 'macadamia nuts' reporting. Fat content is exceptionally high at approximately 76 percent by weight, the highest of any commonly-consumed tree nut, so intrinsic kernel density is elevated relative to nuts like walnuts or pecans that carry more water and starch.

Related products: chopped, halved and pre-broken macadamia pieces would each pack denser than whole intact kernels and would earn separate entries when a second authoritative source becomes available. King Arthur does not list chopped or ground macadamia variants. Macadamia flour, sometimes marketed as 'macadamia meal,' is a distinct product with density set by grind fineness rather than kernel geometry, and has no King Arthur reference for comparison. Macadamia butter, like other nut butters, sits in the fat category rather than milled.

Macadamia kernels are placed in the milled category alongside other whole and chopped nuts. The category rule tracks physical packing behavior rather than milling: whole kernels pack by scoop with air gaps in the same way that whole grains and seeds do. The 10 percent category tolerance applies here, and the 11.19 percent observed gap is a genuine physical disagreement rather than an arithmetic error in either source.

No standards body publishes a bulk density for macadamia or other tree nuts. Codex Alimentarius has a standard for macadamia kernels covering moisture content, defect tolerances and grade classification but not physical density. Two authoritative sources with an over-tolerance gap and no method documentation to arbitrate, so this entry is held at low confidence and range-published until a third independent source or a documented fill method resolves whether both figures reflect real but different kernel-state fills.