成本與售價

line      = grams used × price paid ÷ grams in the pack
direct    = materials + packaging × units + minutes ÷ 60 × hourly rate
total     = direct × (1 + overhead %)
per unit  = total ÷ units

margin    = (price − cost) ÷ price      # a share of the price
markup    = (price − cost) ÷ cost       # a share of the cost
price     = cost ÷ (1 − margin)         # for a target margin

• Cost of an ingredient in the batch = grams used × price paid ÷ grams bought. The price and the pack size are the maker’s own, from the invoice, so the figure is what this batch actually cost them.
• Business Development Bank of Canada, "How to set the right price for your products or services": gross margin is gross profit as a percentage of revenues; the markup is expressed as a percentage of cost of goods sold or cost of sales. So margin = (price − cost) ÷ price and markup = (price − cost) ÷ cost, and the price for a target margin is cost ÷ (1 − margin).
• Overhead is taken as a percentage of the direct costs — materials, packaging and labour — which is how a maker who knows last year’s rent, insurance and fees as a share of last year’s direct spending can carry them into one batch. — A percentage is a simplification. It is only as good as the year it was measured over, and it moves when production volume does.