Par level calculator

How the numbers are worked out

• Par level is the stock you want on the shelf right after a delivery: what you use between deliveries, plus a safety buffer.
  par = (weekly use ÷ deliveries per week) × (1 + buffer)
• Reorder point is the level at which to place the next order: what you use while you wait for the delivery, plus the same buffer.
  reorder point = (weekly use ÷ days open) × lead time + buffer
• Buffer. The default is 20% of one delivery cycle's use. One restaurant-software guide suggests setting aside around 20 to 30% of weekly use as safety stock; the right figure for you depends on how reliable your deliveries are and how much a stock-out costs you.

Guides differ on the exact formula, so treat the output as a starting point. For example, with 60 lb of chicken a week, two deliveries a week, one day of lead time and a 20% buffer: you use 30 lb per delivery cycle, the buffer is 6 lb, so par is 36 lb, and the reorder point is about 15 lb.

Using the results

• Round to how you buy. If a case is 10 lb, a par of 36 lb means 4 cases. Round up for items you cannot run out of, down for items that spoil fast.
• Check shelf life. If you enter shelf life, the calculator warns when deliveries are further apart than the item keeps.
• Review often. Menu changes, seasons and a new supplier all change usage. Recount and adjust every few weeks, then keep adjusting.