Inventory and order quantity calculator

What you will enter

• Expected usage per day (units / day): In one consistent unit (pounds, cases, portions). Base it on the sales forecast and recipe yields, not on last week's purchases.
• Days this order must cover (days): From delivery until the next delivery arrives, including the lead time. Half days are fine.
• Deliberate safety stock (units): A chosen buffer for forecast error. Enter 0 if you do not hold one.
• Counted usable stock (units): From a physical count, excluding anything expired, damaged or committed elsewhere.
• Confirmed inbound stock (units): Orders already placed that will arrive before they are needed. Enter 0 if none.
• Units per case (units): How the supplier sells it. Orders are rounded up to whole cases.
• Usable shelf-life days (days): Days the product stays usable after delivery under your storage conditions.
• Storage capacity (units): How much of this item you can hold in the same unit, considering everything else that shares the space.
• Delivered cost per case ($): The quoted price including delivery. Enter 0 if unknown; the cost line will read 0.
• Minimum cases the supplier or deal requires (cases): A vendor minimum or the quantity a discount requires. Enter 0 if none.

The formula

Need = max(0, usage per day × days + safety stock − counted usable stock − timely inbound). Cases = need ÷ case size rounded up, raised to any supplier minimum. Projected stock = counted + inbound + ordered units, checked against storage capacity and usage × shelf life.

A worked example

Fictional example: 16 units a day for 5 days is 80, plus 10 safety stock is 90. Counted stock of 25 and 20 confirmed inbound leave 45 units to order. Ten-unit cases mean 5 cases (50 units) at $150. Projected stock is 95 units: within the 100-unit storage limit and the 112 units (16 × 7 days) that can be used before expiry.

How to use the result

Deduct what you have once, and only if it is usable

Counted stock and confirmed inbound both reduce the order. Expired or committed stock does not count. A delivery that arrives after it is needed does not count either.

A discount cannot create usage

If a deal requires more cases than you can use before expiry or store safely, the tool says stop. The saving on the invoice becomes waste on the shelf.

The formula recommends; the count confirms

Ordering without counting hides the error until the walk-in is full. Count first, order second, and compare what arrived against the invoice with the receiving template.

Questions owners ask

What unit should I use?

Any unit, as long as usage, stock, case size and capacity all use the same one. Mixing pounds and cases produces nonsense that looks precise.

How do I set the safety stock?

Decide it deliberately from how wrong your forecast has been and how bad a stock-out is for that item. It is an input, not a result, and it is not permission to overbuy.

Does this handle several products at once?

One item per calculation. Use the par and order sheet template for the whole order list and bring a doubtful line here to check it.

Keep working on the decision

• Read: purchasing, pars and the order that does not spoil
• Cost a recipe from purchased ingredients
• Supplier quote, par sheet, receiving and credit templates
• New to percentages? Start with restaurant math from zero.
• Add this decision to your guided opening plan

Sources and scope

• FDA Food Code (model code; adopted and modified locally)
• U.S. Small Business Administration: Plan your business (market research, business plan, startup costs)

Planning estimates based on your inputs. Check the assumptions against your actual quotes, recipes and operating records. Not legal, tax or accounting advice.