How to Pick the Right Water Heater Size

Choosing a water heater size can be overwhelming. Not only does this appliance need to meet your needs, but it also has to fit in the available space you have in your home. At Roberts Plumbing Hydro Jet & Rooter, we’re here to help you make the right decision and ensure a worry-free water heater installation. We share helpful tips on sizing your water heater.


The first-hour rating (FHR) refers to how much your water heater will produce hot water in an hour. This rating, determined by your hot water usage during the busiest time of your day, is crucial to calculating the appropriate water heater size. An FHR that doesn’t match or exceed your hot water needs may cause the unit to work harder than needed, prompting an untimely water heater repair in Chatsworth, CA.


The number of people in your household plays a key role in determining the right size for your hot water heater replacement. Below are estimates of the capacity you need to look for if you are opting for a tank-type unit:

  • 1 to 2 people: 23 to 36 gallons
  • 2 to 3 people: 36 to 46 gallons
  • 3 to 4 people: 46 to 56 gallons
  • 5 or more people: Over 56 gallons


When your water heater is too small or too large for your needs, you are likely to run into costly issues in the long run. Undersized water heaters prematurely wear down as they need to exert more effort to keep up with your hot water demands. On the other hand, oversized units waste significant amounts of energy because it heats more water than necessary. They are also more expensive upfront and use more energy than appropriately sized heaters. When you turn to us for water heater services, rest assured that we’ll help you make the right choice.

Whether you need a traditional or tankless water heater, Roberts Plumbing Hydro Jet & Rooter can help you find the best one for your needs and budget. Get in touch with our team today to schedule an appointment.