Ounces first, then grams
Every other locale in this tool opens in grams and millilitres. English is the exception: results display in ounces and pounds by default, with a metric toggle next to the total. That’s not a translation choice — US recipes, butcher counts, and catering order forms are written in oz and lb, and converting in your head while placing an order defeats the point of a calculator. Underneath, every calculation still runs in grams and millilitres; imperial is a display layer, not a separate formula.
Portion sizes, and the one case that needs raw weight
A seated dinner runs 4–6 oz of protein per person, a buffet with boneless cuts runs 6–8 oz, and bone-in cuts (ribs, chicken quarters) run 10–12 oz to cover the bone weight you’re not eating.
BBQ needs a different number. Smoked, slow-cooked meat loses roughly 35% of its weight to rendered fat and moisture, so 200 g of cooked brisket or pulled pork on the plate takes about 308 g of raw meat into the smoker. That’s exactly where the old butcher-counter rule — “a half to three-quarters of a pound raw per person” — comes from. This tool applies that 35% loss only to BBQ; every other meat option uses its serving weight directly.
How far a bottle goes
A 750 ml bottle of wine pours 5 glasses; the same bottle in sparkling wine pours 6 flutes, since a flute holds less. A 750 ml bottle of spirits gives 16 pours at a 45 ml shot, or 12 at a 60 ml cocktail measure — the numbers behind every alcohol total this tool produces.
Appetizers are counted for the whole party, not per hour
A common rule of thumb says 8–12 pieces per guest per hour. Applied to a 4-hour party, that’s 32–48 pieces per person — about three times what the “12–15 pieces total” guidance recommends. The two rules measure different things, and mixing them over-orders badly. This tool uses only the total-party method, capped at 24 pieces per person regardless of how long the event runs.
Alcohol pacing, and what to double-check
The pacing on the alcohol tab — two drinks the first hour, one per hour after — comes from US liquor retail and catering guidance, not a peer-reviewed source. The calculator asks only for your count of adult guests, never their ages, since legal drinking ages differ by country. Two other figures carry the same caveat and show “estimate” in the results: the 1:3 alcohol-to-mixer ratio for highballs (45 ml spirit to 135 ml mixer), and counting a teenager as a full adult portion.
Total food, across all courses, should land between 450–570 g per person (roughly 16–20 oz). Well outside that band usually means the guest count or event length is off. Adjustments apply automatically: lunch events subtract 12.5% from food, serving alcohol adds 10%, and a 12.5% safety buffer sits on top. For a drop-in or open-house format, the tool assumes only 75% of invited guests show.