8 Reales Carlos IV 1790: Value & Real Prices

If you inherited or found an 8 Reales Carlos IV dated 1790, here is the honest answer: it is a real silver coin with a built-in floor value tied to its metal, and the best examples sell for a solid premium above that. Most circulated pieces trade in the low-to-mid double digits in USD, while sharp, certified examples can reach several hundred dollars. Condition is what separates a 30-dollar coin from a 300-dollar coin.

This is a Spanish colonial silver piece, struck in Mexico City (the Mexico mint) while it was still a Spanish colony, not the independent Republic of Mexico. The "8 Reales" was the famous Spanish silver dollar, the coin that circulated worldwide and helped inspire the US dollar. That international history is part of why there is steady collector demand for it in 2026.

What you actually have

The 1790 issue carries the bust of King Carlos IV of Spain on the front and the Spanish coat of arms on the back. A note that matters for authentication: the very earliest 1790 strikes were made using the portrait of the previous king, Carlos III, with Carlos IV's name, because the new royal portrait had not arrived yet. Genuine transitional pieces like that carry a premium with collectors.

Hard specifications, keep these exact:

• Denomination: 8 Reales
• Year: 1790 (single year for this specific bust type)
• Metal: Silver, .900 fine (90% pure silver)
• Weight: 26.98 grams
• Diameter: 39 mm
• Edge: incuse (patterned) edge
• Mint: Mexico City
• Assayer: FM

At .900 fineness and 26.98 grams, the coin contains roughly 24.3 grams of pure silver, about 0.78 troy ounces. That silver content is your floor. No matter how worn the coin is, it is worth at least its melt value, and it always has a buyer.

What it is worth in USD

There is no single price. Value moves with condition (grade), whether it has been cleaned, whether it is certified, and the silver spot price on the day you sell. Here is a realistic framework rather than a fake exact number.

Condition	What it looks like	Approximate value (USD)
Heavily worn / damaged	Flat details, scratches, holed or cleaned	Melt value, roughly 20 to 30 USD
Circulated, honest wear	Readable date and design, moderate wear	40 to 100 USD
Lightly circulated	Sharp details, minimal wear	100 to 300 USD
Mint state / certified high grade	Full detail, original luster, NGC or PCGS graded	400 to 1,500+ USD

Those ranges assume a genuine, uncleaned coin. Cleaning is the single most common way people destroy value on colonial silver. A wiped or polished 8 Reales can lose more than half its collector value because grading services and serious buyers can spot it instantly. If your coin looks too shiny or has fine hairline scratches all over, it was probably cleaned.

Rare varieties and mint errors (genuine off-center strikes, die rotation, the Carlos III transitional portrait) can push value well beyond the table above, but true errors are far rarer than social media suggests. Most "error" coins are just post-mint damage.

The myth to ignore

A common belief is that any 200-plus-year-old coin must be worth thousands. It is not automatically true. Millions of 8 Reales were struck across the colonial period and they circulated globally, so the type is not scarce by itself. What creates real value is a high grade, a scarce date or assayer combination, or a verified variety. An average worn 1790 is a nice historical piece worth its silver plus a modest premium, not a lottery ticket.

How to tell if yours is genuine

Counterfeits of colonial 8 Reales exist, so check before you celebrate or sell.

1. Weigh it. A genuine coin is 26.98 grams and 39 mm. If yours is noticeably light, heavy, or the wrong size, be suspicious.
2. Check the edge. It should have an incuse (pressed-in) decorative edge, not a plain or reeded one.
3. The ping test. Genuine .900 silver produces a clear, ringing, high tone when balanced on a fingertip and lightly tapped. Fakes made of base metal sound dull and short. This is a hint, not proof.
4. Look at the details. Cast fakes often show a soft, mushy strike, a seam on the edge, or bubbles in the surface.
5. Get it certified. For any coin you think is worth real money, submit it to NGC or PCGS. Certification confirms authenticity, assigns a grade, and roughly doubles what buyers will confidently pay.

Where to sell it

You have a few solid options depending on how much time you want to spend:

• Certified coin dealers and auction houses. For a high-grade or possibly rare example, houses like Heritage Auctions or Stack's Bowers handle world coins and get you the best exposure to serious buyers.
• Local coin shops. Fast and convenient, but expect a wholesale offer, especially if the coin is not certified.
• The Pesoteca buy-and-sell forum, where collectors of Mexican and colonial coins trade directly. Post clear photos of the front, back, and edge, plus the weight.
• Verified numismatic shops in our dealer directory for an in-person appraisal.

Before you sell, photograph both sides and the edge in good light, weigh the coin, and compare it against the grade ranges above. Read our coin grading guide so you can describe your piece accurately, and see the full Colonial 8 Reales series for how yours fits the type. Do not sell to the first buyer who lowballs you on a fast Facebook offer.

Not sure what grade yours is or whether it is a rare variety? Post photos of the front, back, and edge in the Pesoteca forum and let collectors weigh in before you sell.

This piece belongs to the reign of Carlos IV of Spain (1788-1808). Son of Carlos III. His reign coincided with the French Revolution and with the Napoleonic wars that ended in the abdications of Bayonne.

The government of New Spain in 1790 was in the hands of Juan Vicente de Güemes, second Count of Revillagigedo, promoting the first population census of New Spain.

The numismatic type of the piece is bust, introduced in 1772 under Carlos III. The obverse shows the portrait of the king in the neoclassical style and the reverse the royal crowned shield with the Golden Fleece. The edge is laureate or corded, and all specimens were struck on a screw press, with Latin legends spelling out the monarch's titles and dignities.

The Mexico Mint had migrated to the bust standard in 1772. Under Carlos III and Carlos IV the highest annual output of struck silver in the viceroyalty was recorded, feeding trade with the Philippines via the Manila Galleon and the payment of the subsidy to the Antilles. The assayer's initials declared on the piece are FM, an official of the Royal Treasury charged with certifying the silver fineness (0.930 and later 0.903) per viceregal standard.

The Krause catalog references this piece under KM#108, useful for cross-checking the listing with international auction records.

Year of the start of the second viceroyalty of the Güemes family with the second Count of Revillagigedo, who organized the first population census of New Spain.