Chia seeds

One US cup of chia seeds weighs between 148 and 168 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 chia, raw chia seeds, black chia, white chia, salvia hispanica seeds.

Two sources 13.5 percent apart, outside the 10 percent milled tolerance, so this entry publishes the range rather than a single figure. King Arthur's Ingredient Weight Chart lists 'Chia seeds' at 1/4 cup = 37 g, extrapolating to 148 g per cup and 0.6255 g/mL. USDA FoodData Central lists chia at 168 g per cup, implying 0.7101 g/mL, but with an important sourcing caveat: USDA's SR Legacy record for chia (FDC 170554) publishes only per-100g nutrient data and has no direct cup portion. The 168 g figure is drawn from USDA FNDDS (FDC 2707590), a standardized dietary-survey measure used for national intake studies. FNDDS is authoritative USDA data but its portions are standardized estimates rather than direct laboratory measurements of the specific food.

The FNDDS figure of 168 g per cup is identical to USDA's figure for whole flaxseed, which sits in another entry on this site as the upper end of a 140 to 168 g range publish. Whether this coincidence reflects a real similarity in the packing behavior of small hard seeds (both chia and flaxseed being small ovoid seeds under 6 mm) or a shared FNDDS standardization convention is unclear from the published documentation. Third-party aggregators including cookconvertapp, cuporgram and gramsinacup largely cite 168 to 170 g per cup, suggesting the FNDDS figure has become the working consensus in the aggregator ecosystem regardless of its methodological basis.

Chia seeds are exceptionally small: approximately 2.1 mm by 1.3 mm by 0.8 mm on average, with individual seed masses around 1.3 mg. Small hard particles typically pack denser than large ones because they fill gaps more efficiently, and chia at 168 g per cup (density 0.7101 g/mL) is physically consistent with what would be expected from that geometry. King Arthur's lower figure at 148 g per cup (density 0.6255 g/mL) is consistent with a loose scoop rather than a settled fill. As with flaxseed on this site, small hard seeds are unusually sensitive to fill technique, and gaps of 15 to 20 percent between different filling methods are physically real.

Product variants: black chia and white chia are cultivar-color variants that pack at essentially the same density and are treated as one entry here. Salvia hispanica is the primary commercial species; Salvia columbariae, sometimes marketed as golden chia, is a distinct North American species with slightly different seed size but no separate authoritative cup portion available. Ground chia seed, sometimes called chia meal, packs differently from whole seeds and is not covered here because King Arthur does not list a ground variant. Third-party sources suggest ground chia packs at approximately 175 to 185 g per cup, denser than whole seeds because the ground particles fill some of the interseed voids, but this pattern is the opposite of what flaxseed shows on this site and remains uncertain without direct measurement.

Chia 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 nuts. The 10 percent category tolerance applies here, and the 13.5 percent observed gap likely reflects a combination of fill-method sensitivity and USDA's use of a standardized rather than direct-measurement portion.

No standards body publishes a bulk density for chia. Codex Alimentarius has no dedicated standard for chia at the time of publication. Two authoritative sources with an over-tolerance gap and one source relying on a standardized USDA estimate rather than direct measurement, so this entry is held at low confidence and range-published until USDA SR Legacy or Foundation Foods publishes a direct cup portion or a third independent laboratory measurement clears the disagreement.