So, let's say you just found an old light bulb, and you want to know how much it's worth. Chances are you may be thinking of putting it up for sale, probably on an auction website like eBay.com (and you want to have all the right buyers see it and have a good sale and all that). Or perhaps you intend to keep it, but are still curious about what it may be worth. Some of the most commonly-found old light bulbs can be found on this page. Some of the rarest and most collectible can be seen here. There's also the Auction Archive, if you want to check that out as well. To safely test your light bulb, see here.
Figuring out what an old light bulb may be worth isn't so easy, but let's give it a try. In general, it's best to start with the age of the light bulb, then look at its condition, then look at its overall appeal to a collector or antiques enthusiast. The value of a light bulb is based only on what a very small pool of buyers are willing to pay for one, and even the amount they are willing to pay varies over time. There's not that many light bulb collectors / antique lamp enthusiasts out there. Please use this guide as a general guide only. The only rule to the value of antiques is that there is no rule, they're only worth whatever a buyer wants to pay for them. Supply varies wildly depending on the kind of bulb, and demand has a heavy tendency to concentrate on bulbs that are low in supply. If you desire, you may contact me for additional help. These days, old light bulbs are almost always hugely overpriced when they show up on auction websites, for the following reason:
If you are going to be listing your light bulb(s) on ebay.com, you need to know this: it seems that a lot of ebay sellers have adopted this crazy trend where old light bulbs are put up for sale with totally arbitrary prices, the vast majority of which are totally unrealistic and a fantasy. I have seen many light bulbs being offered with a buy-it-now price that is 3x, 5x, even 10x the typical value of the bulb. So they just sit there, getting relisted over and over for the same insane price, some of them for more than a year, until the seller finally gives up. I don't know why this is happening, but it is a real epidemic. Nobody is going to buy a $5-$10 Varicare 260w carbon heat bulb for $139.90, or a $10 50 watt Edison Mazda bulb for $59.99 (plus shipping), or a $5 (if that) 1000W large GE incandescent bulb for $80... all of which are extremely common finds and are a tough sell even in perfect condition. Even the rarest versions of these bulbs (such as those made in colored glass) aren't worth anywhere near as much. After making various offers for several bulbs (through the "Make an offer" option), I did notice that whenever a bulb is sold for less than its asking price, if you look again at the closed listing it will say that the bulb was sold at full price, even if a much lower price was accepted by the seller. For example, a seller had a carbon light bulb for $125 buy-it-now, but I offered $40 and the seller took the $40, and then the listing page closed and began saying that the bulb sold for $125... Obviously this is confusing people and making them think that antique bulbs are worth far more than they're really worth. It is a problem within eBay itself, and it's wasting everyone's time. Sellers are left unable to realistically price their items. So, just be aware of this weird phenomenon. I can confirm that it is still happening as of May 2021.
As for who buys old light bulbs, from my experience, there's two main kinds of people: 1). light bulb collectors like me, and 2). People who own an old lamp or fixture, who need original bulbs for their lamp. The first (former) group is very small, and are usually after rare items. The second (latter) group is larger and is usually after cheaper, more common items.
The most important thing that will affect the value of your old light bulb is whether or not it is still able to do what it was originally made to do. Does it still work? Is it in good shape? Is the filament intact or broken? If the light bulb no longer works, in most cases it will be worth nothing, or very little, although this depends on what kind of bulb it is (there are a few rare exceptions). If your antique light bulb is in absolutely perfect condition: Working, no glass darkening, no scratches, intact tip, no corrosion, and with an intact label... then clearly you have a winner. But if the glass is darkened from use, or the glass envelope is visibly scratched, or the tip is chipped or broken, or the base is heavily rusted or damaged, or it is missing all labels or any other identifying info, or worse, it doesn't work, then there could be a problem finding a buyer for it. Keep in mind that a bulb from the 1890's in bad shape can still be worth more than a bulb in perfect condition from say, the 1940's, so you should not assume that because a light bulb is in great shape, that someone would buy it. Certain kinds of old light bulbs are extremely abundant, many of them in perfect condition, so don't just factor in the condition. (Here's a tutorial on how to test a light bulb without damaging it. This is especially important for low voltage bulbs, of which many exist).
Rare antique light bulbs are often those that are well known and that were produced in very small numbers, and/or few of them have survived their journey through time. ("antique" generally assumes an age of at least 100 years). A lot of people seem to think that just because they found a bulb that was produced in a small number, or has a rare feature or label, it is worth a lot of money. This is not usually the case. If the bulb in question was not significant in the evolution of lighting history, or is not otherwise well-known for anything in particular, it probably isn't worth much to a collector, and in that case is probably more interesting to a commercial antiques dealer. I've seen bulbs with very unique labels that didn't receive any interest because the seller priced them very high, thinking they were very valuable just because of the unusual label.
It can be safe to say that all bulbs made before the year 1900 will sell at an online auction, working or not (assuming they are at least in good cosmetic shape). These bulbs are very scarce and coveted by collectors. How can you tell if a bulb was made before 1900? A good way is to look at the bulb's base type. Common 19th century bulbs have Westinghouse Pin Bases, Thomson-Houston bases, or early Edison bases, all three insulated either with plaster or with porcelain. Although there are a few exceptions (Westinghouse-based bulbs with black glass / vitrite insulation do exist), the most common pre-1900's bulbs have porcelain insulation on the bottom. A common bulb from that era in absolutely perfect condition can sell for hundreds, while a non-working one in fair shape might sell for around $25, in my experience. Though in the case of most Thomson-Houston based bulbs, they don't seem to sell well if they do not work, as they are not so uncommon, plus many of them were made post-1900. I have bought a few of them before for around $30 in working condition. A non-working Thomson-Houston bulb might take a few tries to be sold successfully on eBay.
Below you can find pictures of early light bulb bases. Note that there are a lot of other early base types. The ones shown below range from "spotted for sale somewhat often" to "very rarely seen", but not so rare that they're never seen:
Below you can see much rarer base types. Most of the base types shown below are REALLY hard to find, and are VERY coveted by collectors. They're mostly in museums by now, and few of them remain "In the Wild". Very few private collectors own bulbs with those bases, usually the better-funded ones who can afford museum-grade antiques. (I'm not one of them, I'm more of a budget collector). In the early days of electric lighting, you could place an order for light bulbs and ask for them to be made with a specific base type, right from the catalog. If you spot a light bulb with any of these base types at a live, in-person auction, being offered for next to nothing... buy it, definitely!
Below you will find two of the most common antique light bulbs. Bulbs like these in excellent working condition commonly sell for about $5-$15 each, but are usually worth nothing in non-working condition or heavily-used condition.
To see more, click here.