Lead Time Demand Calculator Formula

Understand the math behind the lead time demand calculator. Each variable explained with a worked example.

Formulas Used

Lead Time Demand

lead_time_demand = daily_demand * lead_time_days

Weekly Demand

weekly_demand = daily_demand * 7

Variables

VariableDescriptionDefault
daily_demandAverage Daily Demand (units)35
lead_time_daysLead Time (days)14

How It Works

How to Calculate Lead Time Demand

Formula

Lead Time Demand = Average Daily Demand x Lead Time (days)

Lead time demand is the inventory you will consume between placing an order and receiving it. If you sell 35 units per day and your supplier needs 14 days to deliver, you must have at least 490 units available when you place the order (plus safety stock). This calculation is the foundation of reorder point planning.

Worked Example

A product sells 35 units per day on average, and the supplier lead time is 14 days.

daily_demand = 35lead_time_days = 14
  1. 01Lead Time Demand = 35 x 14 = 490 units
  2. 02Weekly Demand = 35 x 7 = 245 units
  3. 03You need at least 490 units on hand when placing an order to last until delivery.

Ready to run the numbers?

Open Lead Time Demand Calculator