Mobile Power Calculator

Calculations Copyright © 2015 Sensata Technologies - The maker of MAGNUM-DIMENSIONS ® inverters.

We have developed the inverter calculator below as a general guideline to illustrate what loads you can run on your 12VDC vehicle's platform. The conclusions made in this calculator are conservative estimations to illustrate the wattage you need compared to the power your vehicle can deliver. Your results may vary.

Derived wattages are based on the assumption you are using a Magnum-Dimensions® Pure Sine, UL listed inverter.

Note: Using a modified sine wave (MSW) inverter will increase the power drawn by the load and the inverter on the batteries and alternator.

For more information, please contact a Magnum-Dimensions representative here.

  • Step 1 - What I Want to Run
  • Step 2 - What Can I Run - Alternator contribution
  • Step 3 - What Can I Run - Battery contribution
  • Results
What I Want to Run

What I Want to Run

Select the devices you will be using.

Minutes / hrAmps (AC)Watts (AC)Amp-hoursWatt-hours
What I Want to Run

What Can I Run - Alternator contribution

Enter the amps of your alternator.

AmpsIdle AmpsIdle WattsMax RPM Power from Alternator
What I Want to Run

What Can I Run - Battery contribution

Enter the number of batteries and Ahr Rating.

Number of Starting and Auxiliary BatteriesBattery Amp-Hour Rating
What I Want to Run


Below is a summary of the load and vehicle information you entered above. This is a generalized understanding of your power system. Your individual results will vary.

Max Wattage Needed (All loads running at once)0
Managed Wattage Needed0
Max Power from Alternator0
Idle Power from Alternator0
Available Battery Watt-Hour0
Max Wattage Available (surge capacity)0+0=0
Managed Wattage Capacity0+0=0