April 4, 2025

Selecting the right size water heater is one of the most important decisions for your home’s plumbing system. It directly affects your comfort, energy efficiency, and long-term costs. Whether you're replacing an existing unit or planning a new installation, understanding the various water heater sizes—and what they’re designed for—can help you avoid cold showers or wasted energy.

In this guide, we’ll break down common water heater sizes, how to choose the right one based on your household's needs, and which sizes are most commonly available.


Why Size Matters

A water heater that’s too small will struggle to keep up with demand, especially during peak usage times like mornings or weekends. On the other hand, a unit that’s too large can increase your energy bills by heating more water than you actually use.

To find the ideal size, consider:

  • The number of people in your household

  • Your family’s peak water usage (e.g., do multiple people shower in the morning?)

  • Types of fixtures and appliances using hot water (dishwashers, washing machines, soaking tubs, etc.)

  • Whether your system uses a storage tank or is tankless


Common Water Heater Sizes and Their Uses


30–40 Gallon Water Heaters

Best for: 1–2 people

Typical use cases:

  • Small apartments, condos, or mobile homes

  • Homes with one bathroom

  • Light hot water usage

Pros:

  • Compact and efficient for smaller homes

  • Lower initial cost and faster recovery time

  • Takes up less space

Cons:

  • May not keep up with demand if you have guests or increased usage

  • Not suitable for homes with high-volume appliances like large whirlpool tubs

Example Models:

  • Bradford White RG240T6N (40-gallon gas): Reliable and built for durability with safety features

  • Rheem Performance 40 Gal. Gas (Home Depot): Popular retail option with a self-cleaning system to reduce sediment


50 Gallon Water Heaters

Best for: 3–5 people

Typical use cases:

  • Most standard single-family homes

  • Two or more bathrooms

  • Families with moderate daily hot water use

Pros:

  • A good balance of capacity and efficiency

  • Handles simultaneous showers, dishwashing, and laundry

Cons:

  • Takes up more space than smaller models

  • Higher energy usage compared to 30–40 gallon tanks

Example Models:

  • Bradford White RG250T6N (50-gallon gas): High recovery rate, long lifespan

  • Rheem Performance Platinum 50 Gal.: Energy-efficient model with Wi-Fi smart control (available at Home Depot)


66–80 Gallon Water Heaters

Best for: 5+ people or homes with high hot water demand

Typical use cases:

  • Large families

  • Luxury homes with multiple bathrooms and soaking tubs

  • Homes with high-capacity washing machines or dishwashers

Pros:

  • Handles heavy simultaneous usage

  • Reduces risk of running out of hot water

Cons:

  • Larger footprint requires more installation space

  • Higher upfront and operating cost

  • Not always necessary—oversizing leads to energy waste

Example Models:

  • Bradford White RE2H80T10 (80-gallon electric heat pump): Efficient for larger homes seeking energy savings

  • Rheem Gladiator 80 Gal. Electric: Durable with leak detection, smart home connectivity


Tankless Systems: A Size-Free Option?

Tankless water heaters, which heat water on demand, don’t have a set “gallon” size—but they are rated by flow rate in gallons per minute (GPM). While they save space and energy, the size you choose (in GPM) still needs to be matched to household needs.

Example:

  • A 2.5 GPM unit may handle one shower at a time

  • A 6.5 GPM unit could handle two showers and a washing machine simultaneously

Considerations:

  • Great for energy efficiency and homes with limited space

  • May require upgrading your gas line or electrical system

  • Higher upfront cost


Tips for Choosing the Right Size

  1. Know Your Peak Hour Demand
    Estimate how much hot water your household uses during the busiest hour of the day. This is often called the “First Hour Rating” (FHR). Match it to the FHR listed on the water heater.

  2. Factor in Appliance Usage
    A high-efficiency washing machine or dishwasher may reduce your water demand—but homes with large soaking tubs or multi-head showers will need more.

  3. Consider Recovery Rate
    This refers to how quickly the water heater reheats after being depleted. Gas models tend to recover faster than electric.

  4. Think About Future Changes
    Planning to expand your family or install a large tub? Go one size up—but don’t overdo it if your needs will remain steady.


Final Thoughts

Choosing the right water heater size is about more than just capacity—it's about balancing comfort, energy use, and long-term value. A 40-gallon unit might be perfect for a couple, while a family of five will likely need at least a 50-gallon or even an 80-gallon tank. And with today’s wide variety of models, including high-efficiency options and tankless systems, there’s a solution for every household.

If you're not sure what size or brand is right for you, a licensed plumbing professional can perform a full household assessment and recommend the best options for your needs.


Serving Pennsylvania & New Jersey

At Applause Plumbing and Heating, we specialize in professional water heater installations throughout Easton, PA, the Lehigh Valley, and surrounding areas. We're proud to offer trusted brands like Bradford White and can assist in sizing, installation, and maintenance. As a licensed and insured plumbing company, we’re one of the top-rated providers in the Easton area. Let us help you find the perfect fit for your home and budget.