Inverter Sizing Calculator

The Inverter Sizing Calculator totals the running and surge demand of every connected appliance, applies a capacity margin, and recommends a continuous inverter rating along with the surge the unit must tolerate.

• Per-appliance running and surge watts
• Add as many appliance rows as needed
• Adjustable capacity margin
• Recommended continuous rating
• Surge requirement stated separately

1. Add a row per appliance with running and surge watts.
2. Set the capacity margin.
3. Read the recommended rating and the surge to confirm.

Example: 800 W plus 300 W running with an 1800 W combined surge and a 25% margin -> 1375 W required, so choose a 1500 W inverter able to deliver about 1800 W of surge.

• Surge is sized explicitly, which is what actually trips undersized inverters
• The margin keeps the unit off its continuous limit