To set par levels for kitchen prep, calculate the average amount of each prepped item you use per service, add a safety buffer based on shelf life and demand swings, then prep up to that number daily. The formula is simple: Par level = (average daily usage × days of coverage) + safety stock. Items that spoil fast get tight pars and frequent prep; shelf-stable items get higher pars and less frequent prep. Done right, par levels stop you from over-prepping perishables that end up in the trash and from under-prepping items that trigger a frantic, wasteful mid-rush scramble.
Here's exactly how to do it.
A par level is the target quantity of a prepped item you want on hand at the start of service. It's not how much you order — that's an inventory par. A prep par is the finished, ready-to-use amount: diced onions, portioned proteins, blanched vegetables, made sauces.
The goal is to have enough to get through service comfortably without carrying so much that product dies in the walk-in. Food waste in most kitchens isn't from spoiled raw inventory — it's from over-prepped mise en place that can't be held long enough to sell.
You can't set a par on a guess. Track real usage for each prep item over at least two weeks, ideally separating weekdays from weekends.
For each item, record:
Used = Prepped − Leftover. That used number is your real demand.
Do this for 10–14 days and you'll see a pattern. Maybe you prep 4 quarts of marinara a day but only use 2.5 on Tuesdays. That gap is money in the bin.
If you have a POS, pull item sales counts and multiply by the recipe yield per dish. Sold 40 portions of a dish that uses 2 oz of sauce? That's 80 oz of sauce demand — concrete data instead of intuition.
Once you have average daily usage, set the base par to cover the period until your next prep cycle.
Base par = average daily usage × days until next prep
If you prep diced onions every morning and use 8 lbs a day, your base par is 8 lbs. If you prep a sauce twice a week and use 3 quarts a day, you need roughly 9–10 quarts to cover three days.
Always anchor par to shelf life. Never set a par that exceeds how long the item stays usable:
Demand fluctuates. A safety buffer protects you from running out, but an oversized buffer is just sanctioned waste.
A practical buffer is 10–20% above average usage for predictable items, and up to 25–30% for volatile, high-margin, fast-selling dishes where running out costs you a sale. For cheap, ultra-perishable garnishes, keep the buffer near zero — it's better to prep a tiny bit more mid-service than to dump it.
Tie the buffer to consequence:
A flat par for every day is lazy and wasteful. Friday demand isn't Monday demand.
Build at least two par sets:
Layer in known events: reservations, private parties, holidays, local games, weather. If you have 60 covers booked versus a normal 35, scale your pars proportionally that day. Many kitchens write the day's pars on the prep sheet each morning based on the reservation book and a quick gut check on walk-ins.
The most effective system isn't "prep this much" — it's "prep to this much." At the start of each shift, the cook counts what's already on hand and preps only the difference to reach par.
Prep needed = Par level − On-hand inventory
If your onion par is 8 lbs and there are 3 lbs left from yesterday (still good), you prep 5 lbs. This single habit eliminates the most common waste source: prepping a full batch when you already had usable product sitting in the walk-in.
A proper prep sheet should have columns for: item, par, on-hand, and prep-to amount. The cook fills in on-hand, does the subtraction, preps the gap.
Par levels are not set-and-forget. Menus change, seasons shift, sales trends move. Revisit them every 2–4 weeks.
Watch two signals:
A well-tuned kitchen aims for near-zero usable leftover on perishables, with the occasional small shortfall on volatile items being acceptable. If you never run out of anything, your pars are probably too generous and you're quietly throwing money away.
Reducing waste is about pounds and dollars. Two pounds of dumped microgreens may cost more than ten pounds of dumped potatoes. Prioritize tight, accurate pars on your most expensive perishables first — that's where the margin leak is biggest.
When you know the cost per portion of every prep item, you can see exactly what each end-of-night dump is costing you, and which pars deserve the most attention.
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Building costed prep sheets and recalculating par math by hand for every menu change is tedious — which is why most kitchens skip it and keep guessing. PrepSheet turns any recipe into a costed, scalable prep sheet with automatic ingredient costs, yields, and portion math, so your par levels are grounded in real numbers instead of gut feel. If that sounds like it'd save you time and waste, you're welcome to [join the waitlist](#) and be among the first to try it.