Water Heater Energy Efficiency Calculator
Enter in thermal efficiency and standby loss in Btu/hr for your water heater unit. If you need assistance with thermal efficiency and standby loss data, please see AHRI directory for water heater standards.

Thermal Efficiency
 %
Standby Loss
 
Calculated EF:
         
Examples
Thermal Efficiency
80%
80%
90%
90%
Standby Loss (Btu/hr)
624
537
863
776
Calculated EF
.62
.64
.62
.64