Keep the assumptions beside the result.

Test the business case using your own costs and expected use. A calculator can make the assumptions visible; it cannot guarantee savings, payback or increased productivity.

Define the comparison

Choose the current arrangement and the proposed setup, the same period and the same drink quantity. Identify who pays each cost. Personal spending by employees is not automatically a cost the business can recover.

Include the costs that change

Use current equipment or rental offers and actual ingredient prices. Add installation, delivery, servicing, filtration, cleaning and any payment-processing costs where applicable. Leave an unknown cost visibly unconfirmed.

Calculate the difference

Compare total included costs over the chosen period. For an upfront investment, a payback estimate only makes sense when the recurring saving is positive and all relevant costs have been included. Keep the assumptions with the result.

Test sensitivity

Change daily demand, operating days, dose, waste and service scope. Show how lower use or higher costs affect the result. A promising typical scenario should not hide a poor low-use result.

Keep the estimate separate from an offer

Use the calculation to decide what to ask and which products to compare. A formal proposal needs approved configuration, prices, dates and terms.

Build a planning estimate · Compare equipment · Ask about a proposal