Weight of money

When it comes to historical fiction, I’m a stickler for details.  One important detail from “The Fortuitous Meeting” is the price Pero de Belem sets on Oludara: 40,000 réis.  Since this detail is so relevant to the story, I performed careful research to make sure I got the number correct, looking up values on old tables.  I used exactly twice the normal value of a slave at the time.  I also researched all the coins in use and decided that Gerard would pay with a hundred gold coins known as the cruzado.

However, I never did look up the weight of the coins.  It wasn’t relevant to the story and I just asumed that a hundred gold coins would have at least a bit of heft.  But I recently discovered how far off my conception of their weight had been.

It all began when I purchased a couple of coins from the time of Gerard and Oludara, to get a feel for money from that time period.  In the picture below, the coin on the left is a five réis copper coin, and the one on the right is a silver vintém, worth 20 réis.  The coins are worn down, but still retain a good part of their original mass.

I was quite surprised by the difference in size and weight of the two coins.  The silver piece, worth four times the value, has only one-fifth the weight.  It weighs around one and a half grams: so light you can hardly tell when you have it in your hand.

So I went and looked up the original weights of coins at the time, and I confirmed that the weight difference was indeed huge.  At the time, the values of the three metals in use (in coinage) were approximately:

Gold = 130.9 réis/gram

Silver = 11.4 réis / gram

Copper = 0.6 réis / gram

So, 40.000 réis of gold would have been a little over 300 grams, or about the weight of a full can of soft drink.  The same in silver would have been 3.5 kilograms or around 8 pounds.  And the same value in copper would have been 71.6 kilos – just a few kilos below my weight!

We’re all familiar with the cliché of the heavy sack of gold, and gold does have around twice the weight of silver and three times the weight of copper.  However, at the same weight it was worth over ten times the value of silver and over 200 times the value of copper!  So the lightest, most efficient way to travel was in fact by carrying gold.  Thus, the concept of the “heavy purse” becomes quite the opposite.  A heavy sack of gold would be an insane fortune, highly unlikely for anyone to carry around in a purse.  A heavy purse would almost certainly be filled with copper.  To put it into perspective, the four gram (0.15 oz.) engenhoso, a piece of gold at the time, was by itself worth around one pound of copper.

In the story, Gerard says “I came running with a sack of gold weighing me down.”  But I suppose that Coke can’s worth of weight probably didn’t slow him down so much after all. 🙂

4 Responses to “Weight of money”

  1. scott andrews

    that is really neat–and your analysis as well. the relative values of the metals, one assumes, is a result of their relative scarcities.

    i’ve been in European countries where the bills were different sizes–i figured it was ostentation more than anything. 🙂


    • Christopher Kastensmidt

      Thanks, Scott! I mostly wanted to point out that gold and silver pieces aren’t necessarily always the big honkers that some writers make them out to be. That silver I have is the lightest coin I’ve ever seen. The relative values at the time just way overcame the weight differences of the metals. In any case, it was a fun post. I love writing the “hands on” ones.

  2. Asakiyume

    Came here after finishing your story, and clearly yes! A loving amount of research here.

    Regarding the weight of coins, I remember as a child collecting for some cause and being given three rolls of pennies. They were so heavy! And yet their value, together, was only $1.50. The same value in quarters would have weighed much less, as it would take only six quarters to get there (but it takes 150 pennies!)

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