1. Make a list of all the electrical devices and appliances to be run on the generator.

2. For each item on the list, note down the running power in watts. Also include the surge power in watts where possible.

3. Cannot find the wattage of the item? Calculate the wattage using this simple formula: watts = amps x volts

4. Add all the running watts. This is the minimum required running power of the generator.

5. Take the highest value for surge power on the list. Add the additional wattage to the total running watts.

6. In addition to the minimum required power, add a few hundred watts. This is to ensure that the generator can handle any power fluctuations or additional needs in the future.

Note: Not all devices and appliances mention the surge power. To prevent electrical damage and overloading, add a few hundred watts to the total required running power.