How long does the typical gas fired water heater last?

My last 2 water heaters started leaking after around 10 years.

If you replace your anodizing rods on a regular basis, you should get about 20 years out of the average gas hot water heater. When was the last time you replaced them?

There are a lot of factors as to how long a heater will last, but one of the core ones is how well the unit is maintained.

That Mr. Cheapo's heater is still chugging is a good sign. However, bear in mind that softened water also leaves salt (mineral) residue which can build up and cause metal pipes and fittings to deteriorate -- I'm sure you've noticed the residue on your glasses when they come out of the dishwasher, as well as all the spotting in your bathroom and on fixtures. Sodium is sodium so if anyone in your family is on a sodium restricted diet, you need to filter the drinking water first, and get a filter for your shower/bath water (yes, sodium is absorbed through the skin).

I have found that soft water does little to the life expectancy of a water heater.

here in San Diego I see a range of typical replacement of 9-12 years. There is not set timeline but many heater I replace are in this range others go quicker or last longer

I would agree that waiting for it to fail is the best way to determine when.

Both Ann & Ranger have valid points. Many tanks today have the anode rod(s) as part of the inlet & outlet ports instead of being separate fittings, making them a royal PIA to change out.

Most by me have Lake Michigan water and do not use a water softener. In my old house, I had an 8 yr. tank fail in 7 1/2 yrs, the subdivision I'm in now, I've replaced my tank and several of the neighbor's 6 yr. tanks at near the 10 yr. mark. And 7-8 yrs. ago, I replaced a co-workers 9 yr. tank that was 21 1/2 yrs old , that flooded his basement. Most failing tank give a warning, some don't.

My 12 yr. tank cost's a bit more than a 6 or 9 yr tank, but it's getting replaced at the 10 yr.mark anyways. Just to avoid a catastrophe.

Water heaters have different life expectancies. One will leak or the gas burners go bad within a few years, while another of the same brand and model will last for what seems like forever.

Wait until it goes bad before replacing it. You might be throwing away one that would last another ten years.