Addendum

As for cubits, well, they sound related to geometry and thus are better ignored. We have to keep things simple and heroic.

Currency Revolution

We should probably talk about talents more in fantasy, but the problem with that is figuring out what in the world a talent is, a difficulty for both the author and the audience. However, if we just think of it as "a big chunk," it becomes a convenient sort of measurement.

On Height

When Apollodorus (Pseudo-Apollodorus if you want to be mean) declared Heracles to have been four cubits tall, he presumably did not intend to make that legendary figure a target of ridicule. Yesterday's giant is today's manlet it seems. For that reason, be sure to describe your hero in this way: "He was tall and handsome by the standards of your time and place." There, insulated. If you don't want your hero to be tall, yes you do.

On Measurement

Have you ever noticed how confident characters usually are about sizes and distances? I'm sure it's a skill that can be practiced, but it seems like even people thrust into adventure know how long 40 yards are or how big a 56-square-meter object is.