What Size Water Heater Do You Need For Your Home?

When it comes time to replace your water heater, there are some things to consider, like what size you need. Is your water heater the right size? Replacing your hot water heater with the same size that is there now might not be the right thing to do. In this article, we will explain the factors in considering the size hot water heater you need. For energy savings, you need to know what is best before purchasing a water heater. This article makes sure it’s the correct size.

How Old is Your Water Heater?

If the home is new to you and you were not the one who had the last water heater installed, you may want to think about how your family size compares to the previous owners. Since most water heaters last 8-12 years, the needs of the last homeowner may be more or less than yours. 

The water heater has very little to do with the size of the house or the amount of bathrooms. They don’t use the hot water, you and your family do.


Read more about “Signs it is Time to Buy a New Water Heater.”

Family of five sitting on front porch
For a family of 5 people a 60 gallon water heater isa good choice.

What Size Water Heater Do I Need for My Family

The size of your family is the biggest factor in finding out what the best size water heater you will need. Normally, residential water heaters range from as low as 30 gallon tank units, to as high as a 100 gallon tanked hot water heater.  


Most homes have either a 40 or 50 gallon hot water tank, as these are the most frequently found sizes in homes. If your home is 2 bedrooms, or a studio apartment, you may have a 30 gallon electric or gas water heater. Larger homes with over 4 bedrooms may have a gas or electric unit that is larger than 60 gallons.


Hot water heater replacement Carneys Point, New Jersey
Setting the right tempurature on a water heater is vital to saving energy.

How Much Hot Water Do You Use?

How you determine what size water heater you need is by how much you use. A shower takes on average 10 gallons, running a load of clothes take 6-9 gallons, washing dishes by hand takes another 2-3 gallons. 


That may sound like a small amount of hot water, but your water heater has been designed and calculated by peak hour demand or first hour rating.  


If you have 3 or 4 people taking a shower early in the morning, 30-40 gallons of hot water may be used in a short period of time. So a small 40 gallon water heater may not be the best choice. Especially if you or one of the other family members takes a longer shower than normal.


First Hour Rating or FHR

The energy guide sticker on your hot water heater should have a “First Hour Rating” on it. The FHR rating shows how many gallons of water a heater can produce at any given hour.  The first hour rating is the number of gallons of hot water the heater can supply per hour. Starting with a tank full of hot water, of course.


The size of the tank directly impacts the cost of the unit. Bigger tank equals more money to purchase and install. So figuring out how much hot water you need and when is critical when your budget is tight..


This article from the Dept. of Energy gives you good information. https://www.energy.gov/energysaver/sizing-new-water-heater 


Estimating Hot Water Usage

The fast way is to do an occupant to gallon equation. For every member of your house, you can figure 12 gallons of hot water. So if you are a family of three, 36 gallons. You would need to get a 40 gallon water heater. You may get away with a 30 gallon unit, if you plan out your hot water usage. 

Top view of a serene mature woman in bathtub
How you use water matters in picking the right sized hot water heater.

Hot Water Consumption by Activity

Figures according to the Energy Dept. website.

  • Shower 10 gallons
  • Load of Laundry 6-8 gallons
  • Top load Laundry 15-25 gallons
  • Washing Face & Hands 2 gallons
  • Dishwasher 5-7 gallons
  • Shaving .5-1 gallon
  • Food Prep 2 gallons or more
  • Shampoo Hair 2-3 gallons

Figuring hot water usage helps you make sure you have a tank that will work for your home. Once you’ve figured out how much you need, you’d probably want to consult with a plumber to make sure you choose the proper size and that someone properly installed it.

Size Chart for Water Heater By Amount of Home Occupants.

  • 1 Person 20-30 gallons
  • 1-2 People 20-40 gallons
  • 2 People 30-40 gallons
  • 2-3 People 30-50 gallons
  • 3 People 40-50 gallons
  • 3-4 People 40-60 gallons
  • 4 People 50-60 gallons
  • 4-5 People 60-70 gallons
  • 5 People 70-80 gallons
  • 5-6 People 60-90 gallons
  • 6 People 70-90 gallons
  • More than 7 people 80-100 gallons

Other things to think about when replacing a water heater.

Now you might go with the head count in your home for figuring a water heater size. But, you should also consider the size needed for the home’s capacity. Especially if you plan to sell your home in the near future. 


Example would be an empty nest home where you have a 4 bedroom 2 bath home, but only two people live in the house. The two of you could easily get away with a 30 gallon unit. But if the home was sold to a small family of 5 it would be about 50% of their needs as a minimum.  


If you choose a unit for the home’s normal capacity, you would waste energy heating more water than needed. On the other hand getting a small tanked heating unit could cause problems when a home inspection company see’s that the water heater is not up to the home’s occupant normal number.  Which could cost you money when selling, by replacing or deducting from the sale price.


So what are your options?

Water Heater Timers

Smart water heater timers are a great way to save money if your unit is larger than your needs. For a couple of hundred dollars you can purchase and have installed a timer on your water heater. Make your water heater smart. Save money on energy and avoid maintenance headaches. Water heater controller gives you convenient control from your smartphone. Saves you money.


Water heater timers will automatically schedule hot water when needed. This time switch will repeat a preset schedule daily. How many hours does a water heater run per day? A typical water heater runs between 3-5 hours a day. With a timer switch, you can control that. Increasing or decreasing the number of times your water heater cycles.

Have your water heater installed by a professional.

When it comes time to replace your water heater, no advice comes better than that of your trusted local plumber. After all, they replace water heaters day in and day out. They will discuss the size of your family, plus any plans you have in the future. Should you sell your home or have a child or more children. Your local plumbing contractor will have the answers. 

To get a quote in Salem County, NJ fill out the contact form below. Our plumbing companies would love to help you pick the right sized water heater for your plans and needs.

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