That may look like a perfectly innocent question but the devil is in the detail.
Chain wear can't be seen in isolation and should always be considered together with sprocket wear. In that light, wear on a singlespeed is a bit different than wear on a cassette bike.
There are many scenarios, but the two over-riding ones have to do whether you are using a single-speed half-link chain or a standard chain.
Within those two scenarios, the variations are:
Both sprockets have even-numbers of teeth.
Both sprockets have uneven numbers of teeth.
Half-link chains wear twice as fast as standard chains. This is because chain wear on a standard chain only happens on the junctions between two half links and not between pins in the same half link. Keep in mind that a link in a standard chain is a two-part affair, with an outer and inner section being called a link.
In other words, if you put a bit of tension on a worn chain and measure exactly between the various pins you'll find that on the outer-plate link, the pins are still 1/2" whilst measuring across the last pin on the outer-plate chain and the first pin in the adjacent inner-link pin, the distance will be 1/2" plus wear percentage.
The percentage elongation measured on only one link is double the percentage elongation measured over the length of the chain that takes into account equal numbers of inner and outer links.
Now, if you had a singlespeed with a 16-tooth sprocket and a standard chain, it means that only every second cog (that's the name for one tooth on a sprocket) will have worn out of pitch. If the number of cogs are unequal numbered, every cog will be worn equally because with each revolution the sprocket "sees" a different worn or unworn 1/2 link.
If the chain was a 1/2 link singlespeed chain, the wear is accentuated and percentage wear is shown as double of what it would have been on a standard chain. There is no need to apply the even/uneven overlay onto this scenario since all links are equally worn by definition.