You can use our calculators to look at the lifetime cost of a new appliance, the differences in operating costs for air conditioning units (central air and window units), the savings from switching to compact flourescent bulbs and the cost and emission savings of buying one or more blocks of green power.

• Compare the difference in operating costs for the most and least energy efficient units.
  
  
• Calculate the annual operating cost for a central air conditioner
  
  
• Calculate the annual operating cost for a window air conditioner

• Compare the difference in operating costs for the most and least energy efficient models.
  
  
• Calculate the lifetime operating cost for an appliance based on its Energuide ratings

• Calculate how much money you can save by switching to energy efficient lighting

• See the cost and pollution impact of supplementing your power supply with one or more blocks of green power.