What Are the Roman Coin Denominations? Denarius, Sestertius, Antoninianus, and the Rest

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 /collections/coins is built around these denominations. Every coin we list is RIC-catalogued, weighed, photographed obverse and reverse, and backed by a written lifetime authenticity guarantee. This page is the reference companion to the catalogue.

The five core silver and gold 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 aureus was replaced under Diocletian by the solidus (introduced AD 312 by Constantine), a lighter gold coin at 4.5 grams that became the foundation of Byzantine currency for the next thousand years.

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. Pre-Neronian dupondii (Augustus, Tiberius, Caligula, Claudius) cannot be distinguished from asses without metallurgical analysis. 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. The portrait is bare-headed (no crown), distinguishing the as from the dupondius.

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.

The follis is the most common surviving Roman bronze. 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

Four physical attributes let you identify almost any Roman coin to denomination at a glance.

  1. Weight is the most reliable single indicator. Weigh your coin on a digital jeweller's scale. Denarius: 2 to 4 g. Aureus: 5 to 8 g. Sestertius: 22 to 30 g. Dupondius: 10 to 14 g. As: 8 to 13 g. Antoninianus: 3 to 5 g (silver) or 2 to 3.5 g (billon). Follis: 2 to 12 g depending on date.
  2. Diameter separates the silver from the bronze denominations cleanly. Denarius: 17 to 20 mm. Aureus: 18 to 22 mm. Sestertius: 32 to 36 mm. Dupondius and As: 24 to 30 mm. Antoninianus: 21 to 24 mm.
  3. Metal colour identifies bronze sub-types. Bright copper-orange = as. Golden-yellow = dupondius or sestertius (both orichalcum). Silver (or silver-washed surface) = denarius, antoninianus, or solidus. Heavy gold = aureus or solidus.
  4. Crown style on the obverse portrait distinguishes some denominations. A laurel wreath is universal across silver and gold denominations. A radiate crown (a sun-ray circle) indicates dupondius (Nero onward) or antoninianus. A bare head on a bronze coin means as. Empresses with a crescent moon under the bust indicate the antoniniana denomination (the female equivalent of the antoninianus).

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.

  1. 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.
  2. Established dealers (Aurora Antiqua and equivalents). Quality and guarantee terms vary; the best dealers publish full provenance, weight, dimensions, and RIC reference for each coin, and offer a written lifetime authenticity guarantee. Aurora's coin catalogue at /collections/coins follows this practice.
  3. 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.
  4. 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

Aurora's current coin catalogue spans the Augustan through late Severan period (1st century AD through 240s AD), with the heaviest concentration in Severan-dynasty silver denarii. Specific sub-collections:

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?

By surviving numbers, the silver denarius is the most common Roman coin denomination. Tens of millions were struck across the Imperial period (27 BC to AD 240s), and large numbers survive in collections and ongoing finds. Within the denarius, the most common emperors are those who reigned long and minted heavily: Trajan, Hadrian, Antoninus Pius, Marcus Aurelius, and Septimius Severus.

How much was a denarius worth in Roman times?

One denarius was a typical day's wage for an unskilled labourer or a Roman legionary's daily pay (later raised to two denarii under Septimius Severus, then three under Caracalla). Sixteen asses, four sestertii, or one twenty-fifth of an aureus. A loaf of bread might cost half a sestertius; a litre of cheap wine cost about one sestertius; a slave could be bought for anywhere from 500 to 5,000 sestertii depending on age, skill, and origin.

What is the difference between a denarius and a sestertius?

The denarius is silver, small (17 to 20 mm), and weighs 2 to 4 grams. The sestertius is orichalcum (golden-yellow brass), large (32 to 36 mm), and weighs 22 to 30 grams. The denarius was worth four sestertii. A denarius is a daily-use coin; the sestertius is for larger transactions and ceremonial gifting. The sestertius is also where Roman engravers did their finest portrait and reverse-scene work because of the large flan.

What does antoninianus mean?

The antoninianus takes its name from Caracalla, who introduced it in AD 215. Caracalla's official name was Marcus Aurelius Antoninus, so the new coin was called the antoninianus — Antoninus's coin. The denomination was supposed to be worth two denarii but weighed only about 1.5 times as much, making it a profitable debasement for the imperial treasury. By the 260s the antoninianus had only a trace of silver, mostly bronze under a thin silver wash.

Are sestertii rarer than denarii?

Yes. The sestertius was struck in much smaller quantities than the denarius because it was a higher-value denomination and circulated less. Surviving sestertii in collectible condition with good patina are noticeably rarer than denarii of the same emperor, which is why sestertii at high grade reach higher absolute prices than equivalent denarii.

Next steps

Three companion guides if you want to go deeper from here:

And the catalogue: /collections/coins.