Calculate the amount of hot water your house needs. Consumer Reports recommendation on how to quickly calculate water heater size that your family needs. Is your water heater the right size for you house? | Photo credit ENERGY STAR®. A properly sized water heater will meet your household's hot water needs. HGTVRemodels shows you how to pick the right size water heater. Learn how on Learn about new models that can heat up your savings on hot water. Point of use systems typically augment a whole house system when instant or additional hot water is needed. To Choose the Right Water Heater for You Pearl kostenlos artikel, the size of all water heater tanks have increased, while the amount of water sport handy they hold has decreased. KEN GRIFFIN PLUMBING SERVICES, INC. The good news is that just by following a few guidelines, you can find the perfect size water heater: Some suggest that you calculate by the number of bathrooms in your home while others say to go by the number of people in your family. They also work with gas and electric fuel sources.