Markup is calculated using the following formula:

((Ex. Price / (Unit Cost × Quantity)) - 1) × 100

ie: ((10 / (5 × 1)) - 1) × 100
    ((10 / 5) - 1) × 100
    (2 - 1) × 100
    1 × 100
  ∴ Markup = 100%

Net Profit is calculated using the following formula:

(Ex. Price - (Unit Cost × Quantity))

ie: (10 - (5 × 1))
    (10 - 5)
  ∴ Net Profit = 5.00
  

https://wiki.cloudposhq.com/doku.php/start:backoffice:products:unitofsale

During a goods in – EVERY goods in will recalculate the average value.

The average cost is calculated during goods in by looking at the history for that item (in the inwards table). By adding up the qty purchased previously at different cost prices, we can then work out the average and update the stock average.

Items that are set as ghost items (A Pot of beer might be a good example) will always have an average cost of 0 due to not ever doing a goods in on ghost items, recipes and so forth.