Water Heater Calculator

Tank Water Heaters: Sized by capacity (gallons). Larger households need more storage to handle peak demand times. A 40-50 gallon tank typically serves a family of 3-4 people.

Tankless Water Heaters: Sized by flow rate (GPM - gallons per minute) and temperature rise. They heat water on-demand, so you need enough capacity to handle all simultaneous hot water uses.

Temperature Rise: The difference between your incoming cold water temperature and desired hot water temperature. Colder climates require more heating capacity.

Flow Rate Estimates: Shower (2.5 GPM) • Dishwasher (1.5 GPM) • Washing Machine (2.0 GPM)

Replacing a water heater isn't just about choosing the right size. The final installed price comes from a combination of equipment, labor, materials, permits, and job difficulty. Here's a quick guide to what contractors consider when building a quote:

1. Equipment (the water heater itself): Pricing varies based on the type of heater (tank, tankless, heat pump), the fuel source (gas, propane, electric), the efficiency level (standard, high-efficiency, or condensing/heat pump), and the brand or warranty length. Higher-efficiency units cost more up front but often save money over time.

2. Labor: Labor includes the technician's time, skill, and the company's operating costs (insurance, trucks, tools, support staff). Access also matters: a simple garage swap is easier than replacing a unit in an attic, basement, or tight closet. Tankless and heat pump installs typically require more time and expertise.

3. Materials & Code Upgrades: Installs often require additional parts such as shutoff valves, flex lines, fittings, expansion tanks, drip pans, drain lines, venting materials, and possibly gas or electrical upgrades. If the home needs code updates, the installer must complete them as part of the job.

4. Permits & Inspections: Many cities require permits for water heater replacements. Contractors build in the cost of the permit, the time to pull it, and the time to meet the inspector and address any required updates.

5. Haul-Away & Job Difficulty: Old water heaters must be drained, removed, and disposed of. Jobs that require navigating stairs, tight spaces, attics, or crawl spaces take longer and increase labor and haul-away time.

6. Overhead, Warranty & Profit: Professional companies must cover insurance, licensing, vehicles, equipment, office staff, software, warranty support, and other overhead. A reasonable profit margin ensures they can stay in business and honor the warranty years later.