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Par Level Calculator
A par set from what you currently order just encodes your current mistake. Set it from usage and lead time instead.
Common questions
Should par levels differ by day of week?
Yes, often by 2×. A single par for all seven days guarantees you overproduce on Tuesday and run out on Saturday. Set at least a weekday and a weekend par for high-volume items.
How do I find my daily usage?
Opening inventory plus received minus closing, divided by days. For a number that survives a volume change, divide by covers instead of by days and multiply back by forecast covers.
What safety stock should I use?
20% for a reliable supplier and steady demand, up to 50% for volatile items or a supplier who misses. If an item spoils inside the cycle, order more often instead of carrying more.