Methodology

Last reviewed: August 5, 2026

Every calculator on this site resolves to the same reference berry. This page documents those constants, how they are applied, and where the approach breaks down. If you disagree with a figure, you will at least be able to see exactly what you are disagreeing with.

The reference berry

We model a single median cultivated highbush blueberry (Vaccinium corymbosum), the type sold in clamshells in most supermarkets.

Why packing efficiency matters

Berries are roughly spherical, and spheres poured into a container do not fill it completely — air occupies the gaps. Random close packing of equal spheres converges on about 64% of the available volume, which is the 0.64 figure we apply.

This is why you cannot simply divide container volume by berry volume. A US cup is 236.588 mL, but only about 151 mL of that becomes fruit — roughly 142 berries, weighing about 148 g. Ignoring packing would overstate the count by more than a third.

Where these figures come from

Mass and nutritional values derive from USDA FoodData Central entries for raw cultivated blueberries. Dimensional figures reflect typical commercial grading for fresh highbush fruit. Packing efficiency comes from the standard random close packing constant for equal spheres, not from blueberry-specific research.

You can consult the underlying nutritional data yourself at USDA FoodData Central.

Known limitations

We would rather state these plainly than let a confident-looking number imply precision that is not there.

• Wild berries are much smaller. Lowbush or “wild” blueberries can run 40% smaller than cultivated fruit. For wild berries, counts will be substantially underestimated and weights overestimated.
• Cultivar variation is large. Individual berries commonly range from under 1 g to over 3 g. Any single-berry constant is a midpoint, not a description of your fruit.
• Berries are not perfect spheres. They are slightly oblate and deform under their own weight, so real packing in a deep container is modestly denser than the model.
• Frozen berries behave differently. Ice adds volume, and frozen fruit does not settle the same way. Expect a few percent of drift.
• Cost figures are illustrative. The default price per berry is a placeholder that varies enormously by region and season. Override it with your own price for a meaningful result.

Rounding

Calculations are performed at full floating-point precision and rounded only for display. Very large results are abbreviated (K, M, B, T) for readability, which means the displayed figure may differ slightly from the exact value.

Recipe testing

Recipes marked TESTED have been prepared in our own kitchen and the written method reflects what actually worked. Recipes without the stamp are developed from established baking and preserving technique but have not yet been through our kitchen. We label the difference rather than obscure it.

Corrections

If you believe a constant or a formula here is wrong, email nealmedia@yahoo.com with your reasoning and a source. We publish our inputs precisely so they can be checked.