Water heater lifespan calculator
Pick your type and age. You get where it sits in the typical lifespan and what to plan for.
Lifespans reflect commonly cited industry figures for well-maintained units: 8 to 12 years for a conventional tank and 15 to 20 years for tankless. Replacement and running-cost figures are national averages from the Fix or Hire repair-or-replace research. Your actual unit can fall outside these ranges.
How this calculator works
Pick your water heater type and age. Conventional tank units typically last 8 to 12 years and tankless units 15 to 20 years, based on commonly cited industry figures. The calculator places your unit in that range and tells you whether to relax, plan, or budget for a replacement.
Hard water shortens life and regular flushing helps extend it, so those answers add notes but do not change the typical range.
Frequently asked questions
How long does a water heater last?
A conventional gas or electric tank water heater typically lasts 8 to 12 years. Tankless units usually last 15 to 20 years.
Does hard water shorten the life of a water heater?
Yes. Hard water builds scale and sediment, which wears the tank faster. Flushing the tank about once a year helps extend its life.
Should I repair or replace an old water heater?
On a unit near or past 10 years, a repair that only buys a year or two often costs more per year than replacing. Check the warranty first, since many water heaters carry 6 to 12 years of coverage.
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Last updated October 2026. Reviewed by the Fix or Hire editorial team. Estimates only, not a quote.