Ordering GuruPar level calculator (and how to set par levels)
A par level is the amount of an item you want on hand right after a delivery, enough to last until the next delivery arrives, with a small cushion. Set it right and you stop running out on Fridays and stop throwing away what you over-ordered. Enter an item’s numbers below.
The par level formula
Par level = daily usage × (days between deliveries + lead time) + safety stock
- Daily usage is how much you go through on an average day. Take it from your sales or from counts: count the item, count it again a week later, add what was delivered in between, and divide by 7.
- Days between deliveries is your order cycle. A supplier that delivers every Tuesday is a 7-day cycle; twice a week is roughly 3 to 4.
- Lead time is how long the vendor takes from receiving your order to delivering it. If you order Monday for Wednesday delivery, that is 2 days you are still selling from your current stock.
- Safety stock covers busy days and late trucks. Start with one or two days of usage and adjust.
Then, each time you order:
Order quantity = par level − what is on hand, rounded up to whole cases.
The reorder point is the level at which you need to place an order to avoid running out before the delivery lands: daily usage × lead time + safety stock. It matters most for items you order whenever they run low rather than on a fixed day.
A worked example
A café goes through about 24 gallons of milk a week, gets dairy delivered every 7 days, orders 2 days ahead, and keeps 2 days of safety stock.
- Daily usage: 24 ÷ 7 ≈ 3.4 gallons
- Par level: 3.4 × (7 + 2) + 3.4 × 2 ≈ 37.7 gallons
- On order day they count 10 gallons, so they order about 28, rounded up to whole cases.
Setting par levels that hold up
- Start with your top sellers and anything perishable. Those cost the most when the par is wrong.
- Use real usage, not guesses. One week of counts is a start; four weeks evens out the slow and busy weeks.
- Set separate pars for different days if your week is lopsided, for example a higher par for the weekend delivery.
- Review them monthly and after menu or season changes. A par that was right in July is wrong in December.
- Write the par next to each item on your order sheet or order guide so whoever orders only has to count and subtract.
Turning pars into orders
Pars are only useful if ordering uses them. Most businesses keep a list per supplier of what they buy, with the par beside each item, then count, subtract and send the order. Ordering Guru lets you save that list as an order guide for each supplier, load it into a cart in one click, adjust the quantities, and email each vendor its purchase order. If you are not ready for software, our free purchase order template works for the sending part.
Frequently asked questions
What is a par level?
A par level is the quantity of an item you want on hand after each delivery so that it lasts until the next delivery, plus a small safety buffer.
How do you calculate a par level?
Multiply average daily usage by the number of days between deliveries plus the supplier’s lead time, then add safety stock. Order the difference between the par and what you have on hand.
What is the difference between a par level and a reorder point?
The par level is how much you want after a delivery. The reorder point is the low level that tells you it is time to order, which is daily usage times lead time plus safety stock.
How much safety stock should I keep?
One to two days of usage is a common starting point. Keep more for items you cannot run out of or suppliers that are often late, and less for perishables that spoil quickly.
How often should par levels be updated?
Review them at least monthly, and whenever your menu, product range, season or delivery schedule changes.