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Every bulk label carries a unit price per kilogram or litre; EU rules make it mandatory on food above 100 g or 100 ml, and above 50 g or 50 ml for herbs and spices.
The unit price appears on the shelf label next to the selling price. EU price-indication rules set the trigger at 100 g or 100 ml for food generally, and drop it to 50 g or 50 ml for herbs and spices — so even the smallest jars on the spice wall carry a per-kilo figure you can compare.
The comparison itself is one division: price divided by weight in kilograms. That puts a 250 g supermarket pack, a loose scoopful and a 10 kg gravity bin on the same unit, and turns the question of whether bulk is cheaper into arithmetic rather than guesswork.
For your own fill, run the formula in reverse: net grams divided by 1000, multiplied by the unit price, equals what you pay. The net grams come from the tare-and-fill weighing covered on the container tare weights page — packaging weight never enters the calculation.
On narrow screens, swipe or scroll the plate sideways.
The recurring trap is litre-versus-kilo confusion. Scoops measure volume — 60 ml (a quarter cup) to 240 ml (a full cup) — while labels price by weight, and density sits between the two: honey about 1.4 kg per litre, olive oil 0.92 kg, long-grain rice 0.85 kg. A litre price and a kilo price are only comparable after converting with those figures.
Portion maths makes the kilo concrete. At an 18 g dose per double espresso, 1 kg of coffee beans yields about 55 double shots; 1 kg of dry rice cooks up to roughly 2.5–3 kg. Price per kilo becomes price per serving once those two conversions are in hand.
The final check is quantity: a unit price is only a saving if the amount bought gets eaten within its shelf-life months at 15–25 °C — the rotation side of the equation is on the bulk shelf life page.
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