Compare technologies
Tank vs tankless vs heat pump, gas vs electric — head-to-head verdicts by household, fuel and budget, with the trade-offs spec sheets don't show.
Every match-up ends in a verdict See the match-ups
Independent comparisons · No installer sales pitch
Hot water decisions,
Hot water decisions,
made with cold, hard numbers.
Tank, tankless or heat pump? 40, 50 or 75 gallons? We turn spec sheets, efficiency data and 10-year running costs into plain-English verdicts — so you buy once, and buy right.
Every verdict shows its math
Built on DOE UEF listings
Updated Aug 2026
Start here
Three questions. Three answers.
Every water heater decision comes down to technology, size and long-term cost. Pick the question you're stuck on.
Size it right
From 30 to 80 gallons, from 5 to 11 GPM — match capacity to your household's real morning rush, not the biggest unit on the truck.
First-hour rating · GPM · recovery Run the sizing mathCount the true cost
Sticker price is a third of the story. We model energy use, lifespan and maintenance over 10 years — including rebates and incentives where they apply.
10-yr TCO math in every guide See the 10-year math
The lab bench
Tank vs tankless vs heat pump, at a glance
Equipment prices and running costs for a 3–4 person household, on the assumptions this site publishes. Installation labour is local, so we leave it out. Swipe the table on mobile — the row labels stay put.
| criteria | Storage tankgas · 50 gal | Tanklessgas · 9 GPM | Heat pumpelectric · 50 gal |
|---|---|---|---|
| Equipment price | $700–$1,300Appliance only, labour is locallowest upfront | $1,000–$2,000May need gas line and vent work on top | $1,500–$2,400Before utility and state incentives, where offered |
| Energy cost / year | $290–$340UEF 0.60–0.70 | $215–$240UEF 0.85–0.96 | $170–$230UEF 3.0–4.0cheapest to run |
| Expected lifespan | 8–12 yrsAnode-dependent | 15–20 yrsWith annual descalinglongest life | 12–15 yrsSealed refrigerant loop |
| Hot water delivery | 50 gal storedRecovers in about an hour | Endless, 9 GPMBrief cold bursts between uses | 50 gal storedSlower recovery, hybrid boost mode |
| Best for | Tight budgets, straightforward replacements, smaller homes | 2+ bath homes on gas, back-to-back showers, long-term owners | Garages & basements in mild climates, lowest running cost |
Lab verdict
Replacing like-for-like on a budget? Stay with a tank. Gas home, two-plus bathrooms, staying 10+ years? Tankless wins the decade. Have a garage and want the lowest bills? The heat pump's running cost changes the math — read the full comparison before you call an installer.
Equipment prices are typical US retail; running costs are modelled at 64 gallons a day, a 70 °F rise, $1.50 a therm and $0.17 a kilowatt-hour, against DOE Uniform Energy Factor listings. Installation labour is deliberately absent, because it is local and a national figure would be a guess. Your own fuel prices will move these numbers — size your household first.
Sizing tool
What size water heater does your household need?
Undersize it and the fourth shower runs cold. Oversize it and you pay to keep water hot for nobody. Start from how many people live with you.
How many people are in your home?
Tank size
40–50
gallons
Tankless flow
7–8
GPM
First-hour rating
≥ 60
gallons
Quick estimate only — bathrooms, climate and fuel type shift the answer. Read the full sizing guide for the worksheet.
Fresh from the lab
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Our method
How the Lab reaches a verdict
No sponsored rankings, no referral fees. Three steps, same order, every guide.
Collect the specs
Manufacturer data sheets, DOE Uniform Energy Factor listings and warranty terms for every model in a category — logged side by side.
Model 10 years of ownership
Equipment price plus the energy it will burn over ten years, on one published set of assumptions, so a cheap sticker can't hide an expensive decade.
Publish the verdict
A plain-English recommendation by household type — and the runner-up, because the best pick isn't the same for every home.
Read the full method — data sources, cost model and corrections policy.