The client calls: 180 is now 220. The count changed once. If you run on paper and spreadsheets, the recipe sheet, shopping list, prep plan, pack list, quote and purchase orders can now each be wrong in their own way.

Don’t start by multiplying everything by 220 ÷ 180. Start by asking what kind of number each one is.

Quantities that usually scale

Food portions tied directly to the guest count use a scale factor:

Scale factor = new guests ÷ original guests
220 ÷ 180 ≈ 1.2222

A recipe quantity planned at 18 lb for 180 guests becomes:

18 lb × 1.2222 ≈ 22 lb

Keep the recipe’s batch and yield rules. If you only cook full batches or whole pots, turn the scaled number into what the crew can actually make.

Buying rounds differently

A recipe can need 22 lb while the supplier sells 10 lb packs. The buy becomes three packs, not 2.2. Ask whether the extra has somewhere to go, and whether stock you trust on the shelf should come off the order.

Don’t take stock off the buy just because there’s a number for it. A count needs a date, and you need to know what moved since that date before you trust it.

Fixed quantities may stay fixed

Not everything follows the guest count:

  • The number of delivery vehicles may stay the same or cross a capacity threshold.
  • A serving station, induction unit, or coffee urn may be fixed per station.
  • A venue requirement may apply once to the event.
  • A minimum batch may not shrink or grow linearly.
  • Labels and containers may scale by pan, tray, or batch rather than by guest.

An equipment list should keep those counts fixed until someone decides the event needs one more.

Review the money again

At the same illustrative $68 per guest, revenue changes from $12,240 to $14,960. Theoretical food cost may scale close to the guest count, but whole packs, fixed items, minimum batches, and updated supplier prices can move it differently.

Recheck:

  1. Food cost per guest.
  2. Food-cost percentage against the target.
  3. The selling price or fee structure promised to the customer.
  4. Whether the existing quote is still a draft or already a confirmed commitment.

Reissue one plan

The count changed once. Your five spreadsheets each changed on their own. Put the new count on one event, check the numbers, then send out shopping, prep and pack from the one plan you approved.