Planning worked example

Batch Size with annual demand of 12,000 units: a worked example in planning

Here is what the math looks like when conditions slip. We hold every other input steady and drop annual demand to 12,000 units, then walk the calculation through step by step. Estimate an economic batch size using setup cost, holding cost, and demand.

The inputs for this scenario

  • Annual demand: 12,000 units (the input this scenario stresses; the baseline uses 24,000)
  • Setup cost per run: 320 $ (held at the documented default)
  • Annual holding cost per unit: 1.8 $ (held at the documented default)
  • Working days per year: 250 days (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Economic batch size = √((2 × annual demand × setup cost) ÷ holding cost).
  • Recommended batch works out to 2,066 units at these inputs, and this is the headline figure for the scenario.
  • Runs per year works out to 5.81 runs at these inputs.
  • Days of supply works out to 43.03 days at these inputs.
  • Daily demand works out to 48 units / day at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where annual demand sits at 24,000 units and the headline result is 2,921 units, this scenario comes in 29.29% below the baseline at 2,066 units.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to annual demand, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. The classic EBS formula assumes steady demand and constant costs; lumpy demand, shelf-life limits, or shared-tooling constraints can make the math-optimal batch impractical.

Results at a glance

  • Recommended batch: 2,066 units (headline result)
  • Runs per year: 5.81 runs
  • Days of supply: 43.03 days
  • Daily demand: 48 units / day

Run it with your numbers

  • To rerun this with your own numbers, open the live Batch Size calculator, set annual demand to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.