Pumpkin seeds

One US cup of pumpkin seeds weighs between 129 and 160 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 pepitas, pumpkin kernels, hulled pumpkin seeds, dehulled pumpkin seeds, green pumpkin seeds, raw pumpkin seed kernels.

Two sources 24 percent apart, far outside the 10 percent milled tolerance, so this entry publishes the range rather than a single figure. USDA FoodData Central publishes Seeds, pumpkin and squash seed kernels, dried (SR Legacy) at 1 cup = 129 g, implying a density of 0.5453 g/mL. King Arthur's Ingredient Weight Chart lists 'Pumpkin seeds' at 1/4 cup = 40 g, extrapolating to 160 g per cup and 0.6763 g/mL. The USDA figure is confirmed by proportional consistency across cup fractions: 1/3 cup at 43 g and 1.5 cup at 194 g both divide to the same 129 g per cup.

Pumpkin seed kernels, sometimes called pepitas, are among the most orientation-sensitive foods this site tracks. They are approximately flat ovals, roughly 15 mm long by 8 mm wide by 2 mm thick, and can pack in two very different ways depending on how they land in the cup. Face-to-face stacking, where flat sides contact flat sides, produces a dense arrangement close to the intrinsic kernel density (near 1.0 g/mL). Edge-to-edge or random tumbling produces large air gaps between kernels and drops the apparent density below 0.5 g/mL. Any real cup fill lands somewhere between these extremes. USDA's 0.5453 g/mL is consistent with a loose scoop where seeds fall with mixed orientations; King Arthur's 0.6763 g/mL is consistent with a settled or shaken fill where seeds have had a chance to migrate into flat-on-flat contact. The 24 percent gap between the two figures is a genuine physical disagreement, not measurement error.

This orientation sensitivity is the most extreme case on this site. Whole flaxseed shows a 20 percent USDA-to-KA gap driven by fill-method sensitivity of small hard seeds; walnut halves show a 29 percent gap driven by irregular geometry that locks into unpredictable air pockets. Pumpkin seed kernels sit between them, and unlike walnut halves, the underlying physics is well-understood: flat particles have orientation-dependent packing behavior that can be modeled from the aspect ratio. Neither source names its filling method, which is why the range cannot be narrowed further.

Product variants: raw versus dry-roasted pumpkin seed kernels differ by approximately 4 percent in moisture, which slightly increases apparent density after roasting but rarely crosses tolerance. Salted versus unsalted differs by 1 to 2 percent by weight from added sodium, well inside noise. Whole in-shell pumpkin seeds are a separate product with a much lower apparent density because the hollow shell adds volume without significant mass; a cup of in-shell pumpkin seeds weighs approximately half of a cup of hulled kernels, and would earn a separate entry if a second authoritative source becomes available. Green Styrian pumpkin seeds, a hull-less cultivar of Cucurbita pepo grown primarily for oil and snack use, share the same kernel-shape geometry and pack at the same density range as generic pepitas.

Pumpkin seeds are placed in the milled category alongside other whole seeds, whole grains and whole nuts. The category rule tracks physical packing behavior: whole seeds pack by scoop with air gaps in the same way as whole grains and whole nuts. The 10 percent category tolerance applies here, and the 24 percent observed gap between sources is a genuine physical disagreement rooted in the seed shape rather than a measurement error in either source.

No standards body publishes a bulk density for pumpkin seed kernels. Codex Alimentarius has no dedicated standard for pumpkin seed kernels sold as human food at the time of publication. Two authoritative sources with a large 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 the disagreement.