Rome ran on coinage for nearly seven centuries. From the introduction of the silver denarius in 211 BC through the collapse of the Western Empire in AD 476, eight main denominations carried the everyday and ceremonial economy of the largest state the ancient Mediterranean ever saw. This guide explains each , what it is, when it was struck, what it weighed, how to identify it, and what a real example is worth on the market today.
Aurora's coin catalogue at Aurora's coin collection is built around these denominations. Check the individual listing for its attribution, measurements, photographs and any published catalogue reference, alongside Aurora's written lifetime authenticity guarantee. This page is the reference companion to the catalogue.
Looking for the real thing? Browse our Roman coin collection, each piece one of one, individually authenticated, with documented provenance. For the background, see the guide to Roman jewelry.
Roman coin denominations at a glance
This table compares the main denominations of the early Roman Empire, before the third-century currency reforms. It gives face values, not modern prices or fixed metal weights.
| Coin | Metal in the early imperial system | Value in asses | Value in denarii |
|---|---|---|---|
| Aureus | Gold | 400 | 25 |
| Denarius | Silver | 16 | 1 |
| Sestertius | Brass (orichalcum) | 4 | 1/4 |
| Dupondius | Brass (orichalcum) | 2 | 1/8 |
| As | Copper | 1 | 1/16 |
Do not apply these ratios to every Roman coin. The antoninianus appeared under Caracalla in AD 215, while the solidus belongs to the later system under Constantine. Weight, alloy and diameter changed with the issue and period; size alone cannot establish a denomination.
Sources: NGC's early imperial denomination table, the American Numismatic Society's monetary history and CIfA's Roman coin recording guidance.
Five major Roman coin denominations
1. Denarius (silver, 211 BC to ~mid-3rd century AD)
The denarius is the workhorse of Roman silver coinage. Introduced in 211 BC during the Second Punic War, it remained the standard silver coin of the Empire for over four centuries. The early Republican denarius weighed approximately 4.5 grams of nearly pure silver. By the Augustan reform of 23 BC, the standard had stabilized at about 3.9 grams of silver around 97 percent fine.
The denarius weight and fineness declined progressively through the Empire. Under Nero (AD 54-68) the weight dropped to about 3.4 grams and fineness fell to ~90 percent. By the Severan period (AD 193-235), denarii weighed 2.4-3.0 grams at around 50 percent fineness. The denarius was effectively replaced by the antoninianus by the mid-third century, though sporadic issues continued into the 240s.
A typical Republican or early Imperial denarius today retails for €80 to €400 depending on emperor, condition, and rarity. Severan-period female-portrait denarii (Julia Mamaea, Julia Maesa) tend toward €120 to €250 in collectible condition. Late Republican and Republican imperatorial denarii commanding significant historical interest can reach €500 to €2,000.
2. Aureus (gold, 1st century BC to mid-4th century AD)
The aureus was the gold equivalent of the denarius, valued at 25 denarii. The Augustan aureus weighed approximately 7.3 grams of nearly pure gold (~98 percent fineness). Like the denarius, the aureus shrank over time: by Caracalla's reign (AD 211-217) it had dropped to about 5.5 grams. The aureus was reserved for large transactions, military donatives, and ceremonial gifts.
An authentic aureus today is a substantial investment. Common emperors (Trajan, Hadrian, Antoninus Pius) sell from €2,500 for circulated examples through €15,000 for high-grade specimens. Rarer emperors (Otho, Vitellius, Domitian, Severan women) can exceed €50,000 at auction.
The lighter gold solidus replaced the aureus under Constantine in the fourth century. Its standard was approximately 4.5 grams. Diocletian's earlier currency reform was a separate change to the monetary system.
3. Sestertius (orichalcum, 1st century BC to mid-3rd century AD)
The sestertius , Latin for "two and a half" , was valued at one-quarter of a denarius. It is the largest commonly-collected Roman coin, weighing 25 to 28 grams and measuring 32 to 36 millimeters in diameter. The metal is orichalcum, a golden-yellow alloy of copper and zinc that resembles brass.
The sestertius is prized by collectors for the size and depth of its obverse portraiture. The large flan gave Roman die engravers a real canvas, and the surviving sestertii of Trajan, Hadrian, Antoninus Pius, and Faustina are among the finest portrait art of the ancient world. Reverses often depict major architectural projects (Trajan's Column, the Colosseum), conquests (Dacia capta, Judaea capta), or imperial virtues.
Patina on a sestertius is the single most important value factor. A coin with dark, even, adherent green or brown patina (called "cabinet" or "Tiber" patina depending on the look) can be worth ten times the same coin in stripped or scrubbed condition. Typical retail: €100 to €600 for common emperors in collectible condition; €1,000 to €10,000 for high-grade artistic examples; auction records for exceptional pieces exceed €100,000.
4. Antoninianus (silver, then billon, AD 215 to ~AD 295)
The antoninianus was introduced by Caracalla (Antoninus) in AD 215 as a silver coin valued at two denarii but weighing only about 1.5 times as much. The denomination is identifiable by the emperor's radiate crown (a circle of points) and, on coins of empresses, by the crescent-mooned bust.
From its introduction the antoninianus was a debasement instrument. By the reign of Gallienus (AD 253-268) the silver content had fallen to under 5 percent, with the rest being copper or bronze. These late "silver" antoniniani are silver-washed: a thin surface coating of silver applied during striking, which wears off quickly leaving a copper-coloured core. The antoninianus was replaced by Diocletian's monetary reform of AD 294.
Early antoniniani (Caracalla through Severus Alexander) command €150 to €500 in good condition. Mid-third-century billon antoniniani (Gallienus, Claudius II, Aurelian, Probus) typically retail €30 to €120. Rarer issues from short-reigned emperors (Quintillus, Florianus, Saturninus) can exceed €1,000.
5. Solidus (gold, AD 312 to Byzantine period)
Constantine the Great introduced the solidus in AD 312 as a replacement for the increasingly unstable aureus. Standardized at 4.5 grams of high-purity gold (~96 percent), the solidus became the most stable currency of the late Roman and Byzantine world, retaining its weight and fineness essentially unchanged for over 700 years.
The solidus represents the bridge from Roman to Byzantine coinage. Early solidi of Constantine and his successors are heavily collected. Typical retail: €600 to €2,500 for common late Imperial emperors; €3,000 to €12,000 for early Byzantine issues with exceptional portrait quality or rare reverse types.
The three bronze denominations
6. Dupondius (orichalcum, 1st century BC to mid-3rd century AD)
The dupondius was valued at one-eighth of a denarius , half a sestertius, two asses. It is identical in size and shape to the as (the next denomination down) but distinguishable by two features: the radiate crown on the emperor's portrait from Nero onward, and the orichalcum (golden-yellow) metal rather than the reddish copper of the as.
Dupondii are sometimes mis-identified as asses or vice-versa because patination can obscure the metal colour. For earlier issues, compare the full design, measurements and catalogue attribution; a crown or surface colour alone may not settle the denomination. Typical retail: €40 to €200 in collectible condition.
7. As (copper, 1st century BC to mid-3rd century AD)
The as was the smallest commonly-circulated Imperial bronze, valued at one-sixteenth of a denarius. Standard weight: 10 to 12 grams of nearly pure copper, with diameter typically 25 to 28 millimeters. Read the portrait together with the issue, material and measurements rather than identifying the denomination by the headgear alone.
As coins are abundant survivors and form the entry point to many Roman coin collections. Typical retail: €30 to €150 for common emperors in collectible condition; €200 to €600 for early Imperial (Augustus, Tiberius) or rare issues; €1,000+ for exceptional artistic or historical examples.
8. Follis (bronze, AD 294 to ~AD 348)
The follis was the large bronze coin introduced by Diocletian in his monetary reform of AD 294. The early follis weighed about 10 grams with a thin silver wash, much like the late antoninianus. Through the fourth century the follis was progressively reduced in size and weight, reaching about 1 gram by the AD 340s before disappearing.
Late Roman bronze coins are a useful category to explore, but availability varies by type and condition. Typical retail: €15 to €80 in collectible condition; €100 to €400 for sharper or rarer reverse types; high-grade examples of Diocletian, Maximian, or Constantius Chlorus reach €600 to €1,500.
How to identify which denomination you are holding
Use physical features together with the portrait, legends and a published catalogue comparison. No single measurement or portrait detail identifies every Roman coin.
- Weigh the coin: Record the weight and compare it with examples of the proposed issue and period. Weight ranges overlap, and wear or damage can change the measurement.
- Measure the diameter: Record the diameter alongside the weight. Diameter alone does not reliably separate denominations or metals; compare the whole coin with a published type.
- Consider the material: Use the listed or assessed material together with the other evidence. The aureus and solidus are gold denominations. Surface colour alone can mislead, especially when patina or silvering obscures the underlying alloy.
- Compare the portrait: A radiate crown can help distinguish some dupondii and antoniniani, but it must be read in context. On antoniniani of empresses a crescent may appear beneath the bust; this is the same denomination, not a separate female denomination. Neither a laurel wreath nor a bare head identifies a denomination by itself.
For a fuller authentication walkthrough including patina analysis, die-style examination, and weight tolerances, see our pillar guide on how to authenticate an ancient Roman coin.
Reading the inscriptions
Once you know the denomination, the obverse legend tells you the emperor and approximate date. The standard abbreviation pattern is: IMP (Imperator) + NAME + AVG (Augustus) + numbered titles (TR P V = fifth tribunician year, COS III = third consulship). Each numbered title narrows the date within one or two years.
For the full glossary of Roman coin abbreviations , IMP, AVG, CAES, PM, TRP, COS, PP, GERM, DAC, PARTH , and a worked example on a Trajan denarius, see our pillar guide on what the letters on Roman coins mean.
What is a Roman coin worth today?
The retail market for ancient Roman coins is shaped by four factors: rarity, condition, historical interest, and provenance.
Rarity is measured against the published RIC catalogue. Common types (denarii of Trajan, Hadrian, Antoninus Pius , over 100,000 surviving examples each) sit at the low end of the market. Rare types (short-reigned usurpers, unusual reverses, mint variations) command multiples of common-type prices.
Condition in Roman numismatics is graded from Poor through Very Fine (VF), Extremely Fine (EF), to Mint State (MS or FDC). The bulk of the collectible market sits in VF to EF. An EF Trajan denarius might retail at €200; the same coin in MS could exceed €1,000.
Historical interest is independent of rarity. Coins of Julius Caesar (broadly common in Republican context) carry a name premium. Coins of Christian-era emperors with overtly Christian reverses (Constantine, Constantius II) carry a thematic premium. Female-portrait denarii of the Severan dynasty are seeing rising prices as more collectors discover the matriarchal Severan court.
Provenance matters for both legal and value reasons. Coins with documented pre-1970 collection history, named auction-house pedigrees (CNG, Roma Numismatics, Naville Numismatics, Heritage, Künker), or museum-deaccession paperwork command 15 to 40 percent premiums over coins of identical rarity and condition without provenance. Coins from source countries (Italy, Greece, Turkey, Egypt, Bulgaria, Cyprus) without documented provenance face legal restrictions in some jurisdictions and should be approached with caution.
For a country-by-country guide to Roman coin ownership legality, see are ancient Roman coins legal to own.
Where to buy authenticated Roman coins
Four channels exist for buying Roman coins, in descending order of certainty.
- Specialist auction houses (CNG, Roma Numismatics, Naville, Heritage, Künker, Triton). Highest quality, full provenance research, but buyers pay 15 to 20 percent buyer's premium on top of hammer plus shipping. No retroactive guarantee , once the auction closes, the coin is yours.
- Established dealers. Compare the actual listing, supporting records and written guarantee terms. For an Aurora coin, review its individual description and request clarification of any missing measurements, provenance or catalogue references before buying.
- General marketplace listings (eBay, Etsy, Facebook). Variable quality. No vetting. Authentication burden transferred to the buyer. Pricing can be opportunistic in either direction. Not recommended for beginning collectors without independent authentication budget.
- Unsolicited online seller channels (anonymous Telegram, certain social-media sellers). Avoid. Provenance is typically fabricated, prices are bait, and the legal exposure for the buyer is real in EU and US jurisdictions.
Aurora's coin catalogue
Browse the current collections below for individual attributions, condition notes and availability. The selection changes as unique pieces sell and new coins are added:
Every Aurora coin ships from Belgium with full insurance included in the listed price, full provenance documentation where available, and our written lifetime authenticity guarantee. If a coin is ever shown to be inauthentic, we refund the full purchase price. Forever.
Frequently asked questions
What is the most common Roman coin denomination?
Survival varies by period, region and find assemblage. There is no single denomination that is universally the most common; identify the period and evidence being compared before drawing a conclusion.
How much was a denarius worth in Roman times?
In the early imperial system, one denarius equalled four sestertii or sixteen asses, and twenty-five denarii equalled one aureus. These are coin values, not a reliable conversion into a universal daily wage or modern purchasing power.
What is the difference between a denarius and a sestertius?
The early imperial denarius was silver; the sestertius was a larger brass coin. The denarius was worth four sestertii, so the physically larger coin had the lower face value. Measurements and alloy vary by period and issue.
What does antoninianus mean?
Antoninianus is a modern conventional name for the radiate coin introduced by Caracalla in AD 215. Its original name is not securely known. It appears to have been valued at two denarii, although its silver content was lower than that of two contemporary denarii.
Are sestertii rarer than denarii?
There is no useful blanket answer for every emperor and issue. Compare the specific type and condition. In the early imperial system, a sestertius was worth one-quarter of a denarius; its larger physical size did not make it a higher-value denomination.
Next steps
Three companion guides if you want to go deeper from here:
- How to authenticate an ancient Roman coin , the seven physical markers we apply to every Aurora coin
- What do the letters on Roman coins mean , full Latin titulature glossary with worked examples
- Are ancient Roman coins legal to own , country-by-country guide
And the catalogue: Aurora's coin collection.
More from Aurora Antiqua
References
- Online Coins of the Roman Empire, American Numismatic Society and Institute for the Study of the Ancient World
- Online Coins of the Roman Empire: RIC II Trajan 109, American Numismatic Society
- American Numismatic Society: Silver Quinarius of Augustus, Emerita, 25 BCE
- Aureus of Trajan, AD 103 to 111, Münzkabinett der Staatlichen Museen zu Berlin
- Gold aureus of Julius Caesar, Inv. 99.35.113, The Metropolitan Museum of Art, New
- Coin Hoards of the Roman Republic, American Numismatic Society and University College London (Kris Lockyear)
- RPC, Home, Ashmolean Museum, University of Oxford; British Museum Press; Bibliotheque nationale de France
From Aurora Antiqua
We sell authenticated ancient & medieval pieces , each individually examined before listing and backed by a Lifetime Authenticity Guarantee. One of a kind, sold once, never reproduced.
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