1. What is an Electric Hot Water Heater Sizing Calculator?

Definition: This calculator estimates the appropriate size (in gallons) for an electric hot water heater based on household size and average water usage.

Purpose: It helps homeowners and plumbers determine the right water heater capacity to meet a household's hot water needs.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• Size — Water heater capacity (gallons)
• Family — Number of people in household
• Gal/Person — Average hot water usage per person (gallons)

Explanation: The family size is multiplied by the average hot water usage per person to determine the total tank capacity needed.

3. Importance of Proper Water Heater Sizing

Details: Correct sizing ensures adequate hot water supply while maximizing energy efficiency and preventing unnecessary costs.

4. Using the Calculator

Tips: Enter the number of people in your household and average gallons used per person (default 20 gal/person). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's the typical gallons per person value?
A: The average is 20 gallons per person, but this can vary based on shower duration, appliance use, and personal habits.

Q2: Should I round up the calculated size?
A: Yes, water heaters come in standard sizes (30, 40, 50, 60, 75, 80 gallons). Choose the next available size above your calculation.

Q3: When would I use a higher gallons-per-person value?
A: Increase to 25-30 gal/person if your household has high water usage (long showers, frequent laundry, large tubs).

Q4: Does this calculator work for tankless water heaters?
A: No, tankless systems are sized based on flow rate (GPM) and temperature rise. This calculator is for tank-style heaters.

Q5: What if I have energy-efficient appliances?
A: You may reduce the gallons-per-person value by 10-15% if using low-flow fixtures and ENERGY STAR appliances.