Enter the annual demand and the optimal order size into the Time Between Orders Calculator. The calculator will evaluate the Time Between Orders.

## Time Between Orders Formula

The following two example problems outline the steps and information needed to calculate the Time Between Orders.

TBO = WD / (D/Q)

Variables:

- TBO is the Time Between Orders (working days)
- WD is the working days per year
- D is the annual demand
- Q is the optimal order size

To calculate the time between orders, divide the working days per year by the result of the annual demand divided by the optimal order size.

## How to Calculate Time Between Orders?

The following steps outline how to calculate the Time Between Orders.

- First, determine the annual demand.
- Next, determine the optimal order size.
- Next, gather the formula from above = TBO = 250 / (D/Q).
- Finally, calculate the Time Between Orders.
- After inserting the variables and calculating the result, check your answer with the calculator above.

**Example Problem : **

Use the following variables as an example problem to test your knowledge.

annual demand = 500

optimal order size = 20

TBO = 250 / (D/Q)** **= ?