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Does anyone know what the approximate normal lifespan of a regular incandescent (say 60 W, if necessary for an answer) lightbulb was back in the 1960s, 70s or 80s. Note - I am looking for the situation in former times, not what is currently specified for "now" lightbulbs.

Obviously, this would vary depending how often the lightbulb was turned on/off, and maybe other environmental conditions, but I am just looking for a very rough ballpark number, for a lightbulb that was, say, in a bedroom, or living area, somewhere where it would go on and off at least once a day usually, and often a couple or 3 times, and would be lit maybe 4 or so hours per day. Just a rough typical lifespan, like e.g.: "6 months", or "a year or so", or "5 years at least"...something like that, just from your memory of changing lightbulbs.

isherwood
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im-a-dummy--i-know
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  • 1 - While the number of cycles (on/off) matters, the number of hours on is much more important. A bulb on for one hour a day will last approximately 8x as many days as a bulb on for eight hours a day. 2 - Typical numbers are on the order of 1,000 hours, but there are MANY factors that affect it. – manassehkatz-Moving 2 Codidact Feb 19 '18 at 01:25
  • Basic light bulbs are usually 1000 hours with long life bulbs at 2000 hours, a trick some companies use is by providing a 130 v lamp rated at say 60 w , the lamp last longer because it is only running at 115-123v and not producing the full 60w thus can last much longer. – Ed Beal Feb 19 '18 at 14:47
  • Voting to close. This isn't a home improvement question and the answer is readily available on packaging. – isherwood Feb 19 '18 at 15:02
  • If I answer correctly may I cross the bridge of death, ere the other side to see? – Alaska Man Feb 20 '18 at 02:25

2 Answers2

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From 1924 to 1939 the lifetime of an incandescent lamp was not more than 1,000 hours. That's the duration of the Phoebus Cartel, in which the consolidated patent holders agreed on a strategy of planned obsolescence to boost revenues and fine any member that produced longer lasting bulbs. (It was a 30 year plan, the war shortened the 1959 end date.) Prior to that, longevity was a big marketing point. The Centennial Bulb is a famous bulb made by the Shelby Electric Company which has been burning in a California fire house since being installed in 1901.

Given that planned obsolescence is a profitable business model and the complete lack of any radical changes in incandescent lamps, it's a safe bet that 1,000 hours is in the ballpark right from the 60s through the 80s. I suspect most R&D revolved around making them easier to manufacture or brighter.

Matthew Gauthier
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Most quality incandescent bulbs will list right on the package the average life. Like this:

60 watt General Electric package

Note you can read 1000 hours right on the front of the package. If you go further, turn the package over for detail:

Package detail

Cheap bulbs are missing this info because they are cheap and don't last as long. They might last, they might not.

Things that can shorten bulb life include:

  • Too many watts for fixture causes excess heat which shortens life

  • Bad sockets generate excess heat and shorten life

To increase bulb life buy 130volt bulbs (yes they are available), they will be slightly dimmer at 120 volts but last 10 times longer. The same effect can be achieved with a pre-set dimmer, so that the light buld is always dimmed slightly and never at full brightness. Even just backed off full brightness slightly will extend bulb life geometricly.

Tyson
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