Contents
💧 Water Heater Size Calculator
Find the perfect water heater size for your home - Tank or Tankless
Tank Water Heater Sizing
Based on First Hour Rating (FHR) methodology
Tankless Water Heater Sizing
Based on Flow Rate (GPM) and Temperature Rise (ΔT)
Select Simultaneous Fixtures
Choose fixtures that might run at the same time
📋 Your Recommendation
50 Gallon Tank
Perfect for a 2-person household with medium usage
Size Comparison Chart
💡 Important Considerations
📚 Helpful Resources
U.S. Department of Energy
Official water heater sizing guide
Navien NaviSizer
Professional tankless sizing tool
Rheem Water Heaters
Product specifications and guides
A.O. Smith
Water heater selection tools
Noritz Sizing Guide
Tankless water heater resources
EPA WaterSense
Water-efficient product information
How to Use the Water Heater Size Calculator
Step 1: Select Calculator Type
Click on either:
- Tank Water Heater (for storage tank models)
- Tankless Water Heater (for on-demand models)
Step 2: Enter Your Information
For Tank Water Heater: (See Also: Rug Size Calculator)
- Number of people in household
- Number of bathrooms
- Usage pattern (light, medium, or heavy)
- Fuel type (electric, natural gas, propane)
- Peak hour usage (use slider)
For Tankless Water Heater: (See Also: Septic Tank Size Calculator)
- Select your region
- Incoming water temperature
- Desired output temperature
- Fuel type
- Check boxes for fixtures used simultaneously
Step 3: View Your Results
The calculator automatically shows: (See Also: Humidifier Size Calculator)
- Recommended water heater size
- Technical specifications
- Size comparison chart
- Cost estimates
Use the Print Results button to save your recommendation.
Use the Reset Calculator button to start over.
Quick Reference
Fixture Flow Rates:
- Shower: 2.5 GPM
- Bathtub: 4.0 GPM
- Dishwasher: 1.5 GPM
- Washing Machine: 2.0 GPM
- Kitchen Sink: 1.5 GPM
- Bathroom Sink: 1.0 GPM
Regional Water Temperatures:
- USA Southern States: 70°F
- USA Central States: 50°F
- USA Northern States: 40°F
- Canada: 45°F
- United Kingdom: 50°F
- Australia: 60°F
Related Calculator: Generator Size Calculator
