Water Heater Size & Cost Calculator
Answer 5 quick questions for the right size, fuel, and a ballpark installed cost — from a licensed plumber.
Estimates are general U.S. planning ranges, not a quote — local prices, permits, and code upgrades vary. As an Amazon Associate, Plumbing Picks may earn from qualifying purchases at no cost to you.
Water heater sizing — quick answers
What size water heater do I need for a family of 4?
Most families of four are well served by a 50-gallon tank (or a 40-gallon high-recovery gas unit). Peak demand is roughly 48 gallons in the busiest hour — about 12 gallons per person — so you want a first-hour rating near 50 gallons. Use the calculator above to adjust for your fuel and usage.
Is a tankless or tank water heater better?
Tankless gives endless hot water and saves space, but costs more up front and may need gas or venting upgrades. A tank is cheaper to install and simpler to service. High-demand homes with gas benefit most from tankless; for most electric homes a tank is the better value. See our full tank vs. tankless comparison.
How much does a new water heater cost?
A standard 40 to 50 gallon tank typically runs $1,000 to $2,600 installed, while a whole-house gas tankless runs about $2,500 to $5,000 installed including venting and gas work. See our water heater cost guide for a full breakdown.
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