Calculate Potential Savings From Power Managing Your Computers*

Calculator InputsSavings Results
Basic Advanced
Use the advanced calculator inputs below to estimate your energy and dollar savings from activating power management on your computer monitors and your computer boxes (CPU, hard drive, etc.). Following guidance in footnotes, enter data below or use the default settings.
Use the basic calculator inputs below to estimate your energy and dollar savings from activating power management on your computer monitors and your computer boxes (CPU, hard drive, etc.). Enter the number of units to be power managed and the price of electricity (a national commercial average of 7.1 cents per kWh is the default).

For a more advanced calculator, that allows you to adjust your default settings, click on the Advanced tab above.
Monitors: Computer boxes:
Number of Units to Be Power Managed1:
Electricity Cost (¢ / kWh): Restore Defaults
Hours in Workday:
Days in Workweek:
Monitors: Computer boxes:
Number of Units to Be Power Managed1:
Active Power (watts)2:
Sleep Power (watts)3:
% Units Power Managed Beforex:
% Units Power Managed Afterx:
% Units Turned Off After Work4:
% Time Units
Sleep During Workday5:


Energy Monitors: Computer boxes: Totals:
Current Use (kWh):
Future Use (kWh):
Savings (kWh):
Number of Homes Lit6:
Dollars Monitors: Computer boxes: Totals:
Current Cost ($):
Future Cost ($):
Savings ($):
% Saved:
Pollution Prevented Monitors: Computer boxes: Totals:
Lbs CO27:
Tons CO28:
Cars Off the Road9:
Acres of Trees Planted10:

* Power management places your computer into a low-power sleep mode during periods of inactivity. The computer "awakens" upon touching the keyboard or mouse.
1 Number of Units to Be Power Managed is the number of computer monitors or computer boxes (CPU, hard drive, etc.) that need to be power managed. In general, computer boxes are rarely power managed, so enter the number of PCs in your organization as the number of "computer boxes that need to be power managed". However, depending on your organization, computer monitors are sometimes already set to go to sleep. So enter only the number of computer monitors that ARE NOT already set to go to sleep.
2 Active Power is the amount of energy in watts the typical monitor or computer box uses when active. Defaults are set at 73 watts for the monitor, which represent a typical CRT monitor, and 57 for the computer box. If your monitors are flat panel displays, you should use 34 watts. (Numbers based upon EPA data.)
3 Sleep Power is the amount of energy in watts the typical monitor or computer box uses when in a low-power sleep mode. Defaults are set at 3 watts for the monitor and computer box. (Numbers based upon EPA data.)
4 % Units Turned Off After Work is the percentage of units turned off after work. If you turn off your computer box the monitor also shuts down. Therefore, the percentage of computer boxes turned off after work is set to be the "minimum" the monitors are turned off after work. These two inputs may differ at firms where folks are required to leave their computers on. In these firms people sometimes turn off the monitor and leave the computer box on at night. Defaults for both the monitor and computer box are set to 36%. (Based on Lawrence Berkeley National Lab data.)
5 % Time Units Sleep During Workday is the percentage of time the units are in the low-power sleep mode during a typical workday. (In other words, the portion of the workday during which an employee is in a meeting or otherwise engaged so that his or her monitor and/or computer enters sleep mode.) Defaults for both the monitor and computer box are set at 58%. (Based on EPA data.)
6 Number of Homes Lit represents the number of homes that would be lit for a year by the energy saved by power management. Based upon 1,250 kWh/year used on lighting by the average home. (Based on EPA data.)
7 Lbs CO2 represents the pounds of carbon dioxide from electricity generation emissions avoided due to energy savings from power management. Based upon a conversion of 1.43 lbs. CO2 per kWh electricity generated. (Based on Energy Information Agency data.)
8 Tons CO2 represents the tons of carbon dioxide from electricity generation emissions avoided due to energy savings from power management. 2000 pounds equals one ton.
9 Cars Off the Road represents the pounds of carbon dioxide from car emissions avoided due to energy savings from power management. Based upon a conversion of 11,560 lbs. CO2 emitted per year by a car. (Based on EPA data.)
10 Acres of Trees Planted represents acres of forest that would have to be planted to sequester the amount of carbon dioxide avoided due to energy savings from power management. Based upon a conversion of 7,333 lbs. CO2 sequestered per acre of trees. (Based on EPA data.)