Tank water heaters: 12 gallons per person plus 5 per bathroom. Tankless: 1.5 GPM per person. First-hour rating more important than tank size - amount available in peak hour. 40 gal for 2-3 people, 50 gal for 3-4, 75 gal for 5+ people.
Quick Tips
- Always order 10-15% extra materials for waste
- Check local building codes before starting
- Measure twice, cut once — verify all inputs
Frequently Asked Questions
40 gal for 2-3 people, 50 gal for 3-4 people, 75 gal for 5+ people.
Tank cheaper upfront. Tankless saves energy, never runs out, lasts 20+ years vs 10-15.
Amount of hot water available in peak hour. More important than tank size.