Free tool
Make-or-Buy Calculator: Compare Relevant Costs
Compare the same quantity, quality, tax basis and period. Exclude fixed spending that continues either way. Opportunity cost requires a real alternative use.
Use your own assumptions. Inputs stay on your device and are not submitted or saved. Checked: October 2026.
Calculation basis
Making = quantity × variable cost + avoidable fixed cost + opportunity cost. Buying = quantity × supplier price + additional buying costs.
Read the worked example and assumptions · Download the working record — CSV