Convert 4 Femtowatt to Btu (th)/second: 4 Femtowatt in Btu (th)/second
This calculator allows you to convert from Femtowatt to Btu (th)/second and in a reverse direction. To convert from Femtowatt to Btu (th)/second, enter the amount of Femtowatt into the first input and to convert from Btu (th)/second to Femtowatt, enter the amount of Btu (th)/second into the second input.