Units & Servings

Tuna lets you say amounts the way you would say them out loud: two chicken breasts, half the jar, a cup of rice, 300 grams. Underneath, everything converts to one common measure so nutrition, cost, and inventory always agree. You talk natural; Tuna does the math.

Servings and containers

Most amounts in Tuna are one of two package-shaped units:

• Servings: the food's own convenient portion. A slice of bread, a scoop of protein powder, whatever the label or the food defines.
• Containers: servings wrapped the way the store sells them. A box, a jar, a can.

"Two jugs of milk" is a perfectly good starting amount; Tuna knows how many servings live inside.

When you buy something by the container and Tuna doesn't yet know how many servings are inside, it asks once: servings per container. This is the bridge between "one box" and everything Tuna counts in servings, so it can draw the box down as you eat and price a single serving. You'll see the same one-time question on a receipt line, a new pantry item, or a recipe measured by the container, and your answer sticks to that food for next time. Anything with a nutrition label usually fills it in on its own.

Custom units

Plenty of food is counted in units no label mentions: a breast, a stalk, a clove, a "large". These are custom units, and they come from two places:

• Ones Tuna already knows for that kind of food, with real weights behind them, so "2 breasts" is not a guess.
• Ones you add yourself, which stick to the food for next time.

Precise when you want it

Custom units by default, precise on demand. Every amount can be entered in standard units instead (grams, ounces, milliliters, cups), and switching is one tap, never a requirement.

Sometimes a conversion genuinely needs your help: a cup of something Tuna only knows by weight, or a unit it has never heard of. Rather than invent a number, it shows dashes and asks a one-time question. How defaults get picked, how new units are learned, and when the prompts appear is covered in Unit Conversions.