Local LLM Hardware Break-Even Calculator accuracy and testing

Formula source

• Avoided hosted cost = hosted monthly spend * replaceable percent. Local monthly cost = amortized hardware net cost + electricity + maintenance + hosting. Break-even months = net hardware cost / monthly savings.

Test cases

Known limitations

• This page documents the checked-in calculator logic and does not certify results for every real-world edge case.
• Use the result as a planning estimate unless the calculator page states a stricter purpose.

Assumptions

• Quality, latency, staffing, security, and model maintenance are not monetized unless included in monthly costs.
• Hosted prices and local costs are user-entered.
• No usage details are uploaded.

Unit handling

• Hosted API Spend accepts values in $/mo.
• Replaceable Workload accepts values in %.
• Hardware Purchase Cost accepts values in $.
• Residual Value accepts values in $.
• Hardware Life accepts values in months.
• Electricity and Cooling accepts values in $/mo.
• Maintenance and Ops accepts values in $/mo.
• Hosting / Network Cost accepts values in $/mo.
• Monthly Savings is displayed as currency.
• Local Monthly Cost is displayed as currency.
• Avoided Hosted Cost is displayed as currency.

Rounding rules

• Number displays use up to 2 decimal places in the calculator UI.
• Currency outputs are displayed with standard US dollar formatting.
• Input precision follows configured step values where provided.

Version history

Change log