To calculate the conversion factor for electric baseboard to hydronic baseboard, you need to consider the energy efficiency of both systems. Typically, electric baseboards have an efficiency of around 30-40%, while hydronic baseboards can achieve efficiencies of up to 80-90%. By dividing the energy output of the hydronic baseboard by the energy input of the electric baseboard, you can determine the conversion factor. For example, if the hydronic baseboard produces 80,000 BTUs of heat using 40,000 BTUs of energy, the conversion factor would be 2 (80,000 BTUs / 40,000 BTUs).