Is a 50 gallon water heater enough for a family of 4?

Quick Answer

A 50 gallon water heater may be enough for a family of 4, but it depends on your hot water usage habits. The average family uses 50-80 gallons of hot water per day, so a 50 gallon tank could potentially run out of hot water with a family of 4. However, if you install low-flow fixtures, take shorter showers, and spread out water usage, a 50 gallon heater may suffice. Ultimately the right water heater size depends on daily hot water demand.

Hot Water Usage Estimates

Here are some estimates for hot water usage that can help determine if a 50 gallon heater is enough:

  • Shower – older showerheads use 2.5-5 gallons per minute. Low-flow showerheads use 1.5-2 gallons per minute. A 10 minute shower uses 25-50 gallons.
  • Bath – A standard bathtub holds 30-50 gallons of water.
  • Sink – A bathroom faucet generally uses 2 gallons per minute. Kitchen sink faucets may use 2-3 gallons per minute.
  • Dishwasher – An EnergyStar dishwasher uses 3-7 gallons per cycle. Hand washing dishes can use up to 27 gallons.
  • Washing machine – An energy efficient clothes washer uses 15-30 gallons per load.

Adding up some typical daily usage for a family of 4 might look like:

  • 4 showers at 10 minutes each with low-flow showerhead: 4 x 20 gallons = 80 gallons
  • Running kitchen and bathroom sink faucets: ~10 gallons
  • 1 dishwasher cycle: 5 gallons
  • 1 washing machine cycle: 20 gallons

That’s a total of 115 gallons of hot water needed for an average day for family of 4. A 50 gallon water heater would fall short.

Sizing Recommendations

Many plumbers and home experts recommend the following tank sizes as a minimum for families:

  • 1-2 people – 30-40 gallon tank
  • 3-4 people – 40-50 gallon tank
  • 4+ people – 50+ gallon tank

These assume some conservation of hot water use. Families who take long showers, use hot water liberally, have large jetted tubs, or other high demand factors may need a larger tank than the minimum recommendations.

Usage Habits That Lower Demand

Here are some tips that can reduce hot water usage and allow a 50 gallon heater to suffice for a family of 4:

  • Install low-flow showerheads. This can reduce shower water usage from 25-50 gallons to 15-20 gallons per 10 minute shower.
  • Take shorter showers. Reducing shower length from 10 minutes to 5 minutes saves 12.5-25 gallons per shower.
  • Run full loads in the dishwasher and washing machine. This reduces the number of cycles needed.
  • Don’t let faucets run unnecessarily while washing dishes, brushing teeth, etc.
  • Spread out water usage. Shower at different times, run the dishwasher after dinner rather than first thing in the morning.
  • Set water heater temperature no higher than 120°F. This reduces waste from excess heating.

Practicing conservation habits like these can help a 50 gallon tank work for a 4 person family.

Factors That Increase Hot Water Needs

Here are some home features that can increase hot water demand:

  • Large jetted bathtubs
  • Luxury shower systems with multiple heads
  • Tankless water heaters used for space heating
  • Homes with long pipe runs from the water heater
  • Washing machines that use hot water for warm/hot wash cycles
  • Dishwashers without booster heaters
  • Leaking faucets or fixtures
  • Outdoor hot water use for washing cars, pets, etc.

If a home has several of these factors, its daily hot water needs may exceed what a 50 gallon tank can handle for a 4 person family.

Tank vs Tankless Water Heaters

Tankless on-demand water heaters are an option if hot water runs out quickly with a tank model. Tankless heaters provide a constant supply of hot water by heating it as needed. They have a higher upfront cost but can save on energy bills in the long run. However, tankless heaters work best with low-flow fixtures. Families would need to reduce their hot water usage for a tankless model to be effective.

Pros of Tankless Heaters

  • Unlimited hot water – never run out with high demand
  • More energy efficient since not heating stored water 24/7
  • Smaller size than tank models
  • Longer lifespan than tank water heaters

Cons of Tankless Heaters

  • Higher upfront cost – $1000+ investment
  • Need electrical upgrades for whole home models
  • Do not work well with high-flow fixtures
  • Output temperature fluctuates with water usage rate

So tankless heaters can be a good solution for large or high demand households, but require conservation habits to realize their full benefits.

Heat Pump Water Heaters

One other option is a heat pump water heater. These use heat pump technology to pull warmth from the surrounding air to heat water. They are 2-3 times more energy efficient than standard electric tank heaters. Heat pump water heaters have higher upfront costs like tankless models, but the energy savings can offset this over time. They can be an efficient option for households with high hot water needs.

Pros of Heat Pump Water Heaters

  • Much higher efficiency than standard electric water heaters
  • Estimated savings of $100 to $300 per year on utility bills
  • Larger tank sizes available – up to 80 gallons
  • Good for households with high demand

Cons of Heat Pump Water Heaters

  • Higher purchase cost – around $1,000 to $1,500 installed
  • Require more space and proper airflow
  • May need minor electrical upgrades
  • Varying efficiency based on surrounding air temperature

For households that use a lot of hot water, a heat pump water heater can provide big energy savings over its lifetime compared to standard electric models. Their larger tank sizes make them less prone to running out of hot water.


For a family of 4, a 50 gallon tank may be borderline for daily hot water needs. Installing low-flow fixtures, taking conservation measures, and spreading out usage can allow a 50 gallon heater to suffice. But those with luxury fixtures or high demand factors may want to consider a larger tank, tankless, or heat pump model. Get accurate estimates of your home’s daily hot water requirements before choosing the right size water heater. And consult with qualified plumbers to pick the most efficient option for your needs and budget.

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