No way of telling as it'd depend also on the size of the frame. For all "normal" applications chains a sold a tad longer than needed, and are cut to length on assembly on bike.
Good bikes are made in different frame sizes. And dedicated riders often chainge the gearing ratio by replacing either the sprocket or the driver with one with another tooth count than it came with. These things influence chain length, so you see that no one can tell how many links your chain should be. Chains are just about Always bought a Little long, then cut to length on the bike. Faster than counting links. Chain breakers aren't expensive. Either have a shop fit the chain when you buy it, or get a chain breaker (and a quicklink) and fit it yourself. Do note that chain, driver and sprocket wear together, but usually the chain wears the fastest. So sticking a new chain on old sprockets can often lead to the chain skipping and slipping. If you don't know how to measure a chain for wear, better replace aat least chain and driver at the same time.
Most single-speed bikes(particularly BMXes) use a chain that is 1/8" wide. Chains are always bought a bit too long, and then cut to size. Use a chain breaker tool. No one can tell you how many links you need, it depends on the chainwheel/sprocket combo and the size of the frame.
Shaft, belt or chain & sprocket
There's really no telling, it depends on what size your sprocket and driver/freewheel is, and the length of your chainstays. Chains are always bought a little too long, and then cut to size using a chain breaker tool.
sweet tooth, dr. strangeglove, sprocket, glumps, and lots more.
You must have replaced a part. Either the Driver, Sprocket, or backrim. Your ratio isn't set right. with a 16 tooth driver you have to have a 32 tooth sprocket (i think. it might be 36) with a 9 tooth driver, you have to have a 25 tooth sprocket. i don't know how many spokes you need in your rim for either one though. go to a local bike shop and ask about it. sorry i couldn't help much. i havent messed with bikes in a while.
100000000000000000000000000000000000000000000000000 ft --edit-- Stock chain will be a #35 Chain. You can purchase it from many places on the web. While you're at it, change up your rear sprocket to an 80t or so.
About 68.2.A link is an archaic unit of linear measure. There are 100 links in a chain, there are 66 feet in a chain.
grind off the pin that holds the links together and grind off how many links you need and just put a master link on it
There are 100 links in a chain. There are 66 feet in one chain. Therefore, one foot is equal to 100/66 = 1.51 recurring (that is, 1.515151...) links.
15
As many that is needed