How Much is That in Real Money?

Aureus 1 of gold	Denarius 25 of silver
Sesterce 100 of brass [Orichalcum]	As 400 of bronze

It is nearly impossible to compare the value of Roman money to that of modern times, for a variety of reasons. The confident parenthetical conversions prevalent in the literature of two centuries ago now pale in the face of a variety of methodolgical quandries. Changes in the total stock and relative prices of gold and silver produce subsantial divergences between ancient and modern prices calculated in the two metals. While estimates of Purchasing Power Parity [PPP] exchange rates offer some basis for comparison, the absence of a remotely common basket of goods clouds the estimates.

Scholars have proposed quite diverging estimates of the monetary stock in Roman imperial times. According to Goldsmith, at the end of the Augustan age the magnitude was in the order of some 7 billion sesterces, 3 billion in silver coins (that is, 2,895 tons of silver) and 4 billion in gold coins (that is, 309,6 tons of gold), plus a small amount of subsidiary coins. A much higher estimate, almost threefold, was suggested, for the '60 of the II century AD, by R.P. Duncan-Jones: roughly 20 billion sesterces, 880 tons of gold and 5,766 tons of silver.

Under a gold standard, exchange rates are not prices, but are more akin to conversion units, like 12 inches per foot, since under an international gold standard, every national currency unit would represent a specific weight of the same substance, i.e., gold. As such, their relationships would be immutable. Since 1492 there had never been a year in which the growth of the world gold stock increased by more than 5 percent in a single year. In the 20th Century, the average was about 2 percent.

During the 1990s the price of silver was consistently about $300 per ounce [$10 per gram]. At these prices, the aureus would be worth about $100, the silver denarius [25 to the aureus] worth about $4, and a sesterce [4 to the denarius] about $1. Taking the modern value of gold at about $1000 an ounce, an aureus would be worth about $300, the silver denarius [25 to the aureus] worth about $12, and a sesterce [4 to the denarius] about $3. As of mid-2010, the price of gold was over $1200 per ounce, placing an aureus at about $325, the silver denarius at about $13, and a sesterce [at 4 denarii] $3.25.

During the 1990s the price of silver was consistently about $4 per ounce [$0.15 per gram]. From 2005 through 2010 the price of silver averaged about $15 per ounce [about $0.50 per gram], briefly reaching as high as $20 per ounce [about $0.65 per gram]. With 3.9 grams of nearly pure silver, the denarius would have been worth about $0.60 in the 1990s, and about $2.00 between 2005 and 2010. By extension, the sesterce, one-quarter of a silver denarius, would have been worth about $0.15 in the 1990s, and about $0.50 between 2005 and 2010.

Year	Per c.	GDP Index
1	$ 576	1.35
1000	$ 427	1.00
1500	$ 771	1.81
1600	$ 889	2.08
1700	$ 997	2.33
1820	$ 1,202	2.81
1870	$ 1,960	4.59

The Roman economy was no more backward than the early modern West European economy, and late medieval Western European economies were no more backward than 18th century economies. Only the introduction of machinery and modern sources of energy marked a sharp discontinuity and defined a new path of development from the first half of the 19th century onwards. Maddison's view can be summarized by the series of data (in 1990 international dollars PPP) concerning Western Europe and covering almost two millennia.

In the early Empire, a rate of 4 sesterces [1 Denarius] is suggested as the daily wage by a variety of contemporarneous sources. The daily wage rate for male laborers in Rome under the late Republic was estimated [by Duncan-Jones] as 3 Sesterces. This would suggest a modern equivalence of about 1 sesterce = $0.50, that is 1 denarius = $2.00. Other such calculations could set the value of 1 sestertius as the equivalent of as much as $1.50.

item	HS	$	$ / HS
loaf of bread	HS 0.5	$4.00	$8.00
sextarius (~0.5 liter) of wine	HS 1.0	$10.00	$10.00
modius (6.67 kg) of wheat	HS 7.0	$1.33	$0.20
tunic	HS 15.0	$150.00	$10.00
donkey	HS 500	$2,000.00	$4.00
slave	HS 2,500	$0.00	$0.00
	HS	$.	$.1
wheat = 60 pounds per bushel

According to one estimate, at the time of the early Empire, a prostitute charging 8 to 10 asses might have 5 sexual encounters each day [for a total daily income of about 50 asses], while a prostitute charging 2 asses might have 15 to 20 encounters per day [for a total daily income of about 35 asses]. In the late 20th Century, estimates by prostitutes ranged from 3 [sometimes 5 or 6] to 5-9 to 10 to 15 encounters per day. Sources dating from the early Imperial period give prices ranging from 0.25 as to 16 asses and perhaps more. Known examples are about equally weighted at below 2.5 asses and above 3.0 asses. [The Economy of Prostitution in the Roman World] By one estimate modern out-call prostitutes charge a price for full service of about $150 [grossing about $600 and netting about $400 per night], while an inner-city street-walking prostitute might expect to make $45 for a half hour of "service" [grossing about $700 and netting about $150 per night]. [Strippers make more money than prostitutes] These "estimates" - both ancient and modern - are little better than conjectural, but are plausible rough orders of magnitude. These numbers suggest a Purchasing Power Parity exchange rate of [50 asses = $600] = 1 as = $12, to [35 asses = $150] = 1 as = $4.25. With the rate of 4 as to the sesterce, this would set the PPP value of the sesterce at somewhere between about $15 and about $50.

According to the price of gold, the sesterce today would be worth $3.25, by the price of silver, the sesterce today would be worth $2.00, according to general labor rates, 1 sesterce = $0.50, while prostitute prices would set the PPP value of the sesterce at somewhere between about $15 and about $50. Various commodity prices would suggest a value of possibly $10.00. Differing methods produce a range in the modern value of the sesterce at somewhere between $0.50 and $50.00, seemingly rendering any conversion to modern prices problematic at best.

To return to Crassus [played by Charles Laughton in the movie Spartacus], his wealth of 200,000,000 sesterce was said to be unprecedented. In 2010 Forbes estimated that Mexican tycoon Carlos Slim Helu was the richest man in the world, with a fortune estimated at $53.5 billion [Bill Gates was only worth $53 billion]. By 2021 Forbes estimated that Jeff Bezos was the world’s richest for the fourth year running, worth $177 billion, while Elon Musk rocketed into the number two spot with $151 billion, as Tesla and Amazon shares surged. If the sesterce were valued at $10, Crassus would be worth $2,000,000,000. On the Forbes 2010 list of rich people, this would place him just behind #463 William Wrigley [chewing gum] but tied with #488 Charles Bronfman [Seagram liquor]. By 2021 there would be dozens of people worth $2,000,000,000, all tied in 1580th place, including Joe Rogers, Jr of Waffle House and Hamdi Ulukaya, known as the yogurt king, is the founder of America's most popular Greek yogurt brand, Chobani. But if the sesterce were valued at $1.00, Crassus would be worth an entirely unremarkable $200,000,000.