Daily Amp Hour Usage Calculator
In the top portion of this form fill in the description and wattage of each AC item which will be powered by an inverter, and then on the lower portion of the form fill in the DC loads. Make sure to enter in the Watts and the number of Hrs/Wk the item is used. If your browser supports JavaScrip then the rest will be automatically calculated for you by clicking on the "Calculate" button at the bottom. If you don't have a JavaScript capable browser you can print this form and calculate it out manually.
Remember to find watts:   Amps x Voltage = Watts. You can also find some estimated wattages of appliances you may need on our Power Consumption Reference Guide.
AC Loads
List AC load items Watts X Hrs/Wk = WH/Wk
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1)  Total WH/Wk  
2)  DC watt hours per week. Multiply line 1 by 1.15 to correct for inverter loss.
3)  Inverter DC input voltage; usually 12 or 24 volts. This is DC system voltage.
4)  Divide line 2 by line 3. This is total amp hours per week used by AC loads.
DC Loads
List DC Loads items Watts X Hrs/Wk = WH/Wk
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5)  Total WH/Wk  
6)  DC system voltage. Usually 12 or 24 volts.
7)  Total amp hours per week used by DC loads. Divide line 5 by line 6.
8)  Total amp hours per week used by AC loads from line 4
9)  Add lines 7 and 8. This is total amp hours per week used by all loads.
10)  Divide line 9 by 7 days.
This is total average amp hours per day.
Click on the Calculate button
to automatically calculate average amp hours / day
Daily Amp Hour Usage =

[ Power Consumption Reference Guide ]