← Guides

Waltham Serial Number Lookup

Enter the serial number stamped on your American Waltham movement and this decoder estimates the year it was made, using date tables reconstructed from the original factory ledgers. Waltham built pocket watches in Waltham, Massachusetts from 1852 until 1957 — and unlike almost any other maker, every movement can be dated.

Updated · 5 annotated diagrams · ~8-minute read

The short answer

The number that dates your Waltham is on the movement, not the case. Waltham assigned serials sequentially from about 50 in 1852 to roughly 35,000,000 in 1957, so the serial maps to an approximate production year: 1,000,000 ≈ 1877, 20,000,000 ≈ 1915, 31,400,000 ≈ 1943. The tables give the start of a batch, so treat the year as an estimate — and remember the serial dates and identifies the movement but never proves authenticity on its own.

Tool

Waltham Movement Serial Date Decoder

Enter the serial number from the movement (the mechanism inside), not the case. Numbers only — commas are ignored.

Dates are approximate and reconstructed from Waltham's factory ledgers. They mark the start of a production block, so your watch may have been cased and sold one to two years later. Full source databases are linked below.

The American Waltham Watch Company — trading over the years as the American Waltham Watch Co., the Waltham Watch Co., and earlier names — was the pioneer of interchangeable-part, mass-produced watchmaking. Between 1852 and 1957 it built close to 40 million movements, and it numbered them in a single running sequence. That sequence is what makes a Waltham so satisfying to date: match the movement serial to the year block in the factory ledgers and you have a manufacturing date accurate to within a year or two. This guide shows exactly where the number lives, how the decoder maps it to a year, how it differs from the case serial, and why a serial alone can never confirm a watch is genuine.

Where to find the serial number

The single most common mistake is reading the wrong number. The dating serial is on the movement. Open the back of the watch to expose the mechanism, and look for the number engraved on the largest plate, near the ‘Waltham, Mass.’ signature. The number inside the case back is the case serial — a different maker, a different sequence, and no help in dating.

WALTHAM MASS. 20500000 MOVEMENT — dating serial GUARANTEED 20 YEARS C-4471902 case maker mark CASE — do not use to date
Fig. 1 — The dating serial is on the movement plate (left). The number inside the case back (right) belongs to the case maker and does not date the watch.

Opening the watch

Most Waltham pocket watches are open-face or hunter-case. On an open-face watch the movement is reached through a screw-off or hinged case back. On a hunter case (with a spring-lid cover over the dial) the movement is often viewed by opening the front bezel over the dial, or by a display back. If the back does not unscrew by hand, a rubber ball or a proper case wrench avoids scratching — never pry with a knife.

Reading the number

The movement serial is a 4 to 8 digit number with no letters, cut cleanly into the plate. Ignore the smaller numbers next to individual jewels or the patent dates. If the number you found is preceded by a letter or looks like C-4471902, that is the case serial — go back and read the plate itself.

How the number maps to a year

Waltham issued serials in one long ascending line. To date a movement you find the block its serial falls into: the largest year-mark that is still below your number. A serial of 20,500,000 sits just past the 1916 mark and before 1917, so it was made in approximately 1916.

1877 1.0M 1900 9.5M 1915 20.0M 1943 31.4M 20,500,000 lands in the 1916 block → made ≈ 1916
Fig. 2 — The decoder finds the year block your serial falls into. Because ledger marks record the start of each batch, the result is the estimated year the movement entered production.

A century of production, at a glance

Waltham’s output accelerated dramatically over its lifetime. The first million took 25 years; the company then added tens of millions in a few decades before winding down after the Second World War. Knowing roughly where your serial sits on this arc is a useful sanity check on the decoder’s result.

1850 Founded 1877 1 million 1901 10 million 1915 20 million 1939 30 million 1957 Closed ~35M Output accelerated sharply after 1900 — most surviving Walthams date from 1890–1930.
Fig. 3 — Waltham production milestones, 1850–1957. The great majority of movements you will encounter today were made in the busy decades between 1890 and 1930.

Serial number to year reference

The decoder uses the table below, drawn from the published factory ledgers. Each figure is the approximate serial at the start of that year’s production. Find the largest serial that is still below your number — that row is your year.

Year Serial from Year Serial from
185250190514,300,000
18576,000190715,500,000
186020,000190917,600,000
1865180,000191118,100,000
1870500,000191318,900,000
18771,000,000191520,000,000
18801,500,000191720,900,000
18832,000,000191922,500,000
18863,000,000192123,900,000
18904,700,000192424,550,000
18936,300,000192726,100,000
18967,450,000193027,100,000
18999,000,000193528,600,000
19009,500,000193930,050,000
190110,200,000194331,400,000
190211,100,000194833,100,000
190312,100,000195233,700,000
190413,500,000195735,000,000

Abbreviated for readability; the decoder above holds the full year-by-year table (1852–1957). Figures are approximate and mark the start of a production block.

Not sure what you’re holding? Scan it.

Upload clear photos of the dial, movement, and case and get an AI read on the model, likely era, and authenticity signals in under 60 seconds — a fast second opinion before you buy, sell, or send a vintage Waltham for service.

Start Authentication

Why the serial dates the movement, not the watch

In the American pocket-watch era, movements and cases were manufactured and sold separately. A jeweler paired a bare movement with a case chosen by the customer at the counter. That means the serial dates the movement precisely, but the case could be years newer or older, and the two can be re-married at any point in the watch’s life.

Consistent — likely original pairing
MOVEMENT ≈ 1916 CASE STYLE 1910s Eras agree

Movement date and case hallmark era line up. Nothing proven, but no red flags.

Mismatched — re-cased or married
MOVEMENT ≈ 1916 CASE STYLE 1950s 40-year gap

A big gap between movement date and case era means the case was swapped — common, and it affects value.

None of this makes a re-cased Waltham a fake — it is simply how these watches were sold and serviced. But it does mean two things for collectors: first, that the movement serial is the honest date; and second, that a mismatch is worth knowing about, because an original case in good condition adds meaningfully to value.

American Waltham vs. later ‘Waltham’ brands

This is the trap that catches most searchers. The original American Waltham factory closed in 1957. After that, the ‘Waltham’ name was licensed onto unrelated Swiss- and Asian-made watches — wristwatches, quartz pieces, and jewelry-store brands — that share nothing with the Massachusetts factory. The serial table on this page does not apply to those.

Original American Waltham
WALTHAM MASS. 17 JEWELS
  • • Pocket watch, mechanical
  • • Marked ‘Waltham, Mass.’ on the movement
  • • Serial 50–35,000,000 → datable here
  • • 1852–1957
Later licensed ‘Waltham’
WALTHAM SWISS
  • • Often a wristwatch or quartz
  • • Marked ‘Swiss’ / ‘International’
  • • Serial not in the American table
  • • 1960s onward, different owners

Quick test: if your watch is a pocket watch with a mechanical movement signed ‘Waltham, Mass.’, this decoder applies. If it is a wristwatch, a quartz watch, or the movement or dial reads ‘Waltham Swiss’, ‘Waltham International’, or similar, it is a later licensee product and the serial tables here will not date it.

What the serial can and cannot tell you

The serial CAN

  • • Date the movement to within a year or two of manufacture.
  • • Identify the model, grade, jewel count, and size when cross-referenced in a full database.
  • • Flag an internally inconsistent watch (a movement date that clashes with the case era or the dial style).

The serial CANNOT

  • • Prove the watch is genuine — serials were copied, and reproduction dials and hands exist.
  • • Confirm the case is original to the movement.
  • • Date a later, licensed ‘Waltham’ wristwatch.

Treat the serial as the starting point of an identification, not the end of it. For a valuable or uncertain piece, cross-reference the full factory record for the exact grade and run, and have a watchmaker confirm the movement, dial, and case are honest and correct for the period.

Common Waltham serial number questions

How do I find the serial number on a Waltham?

Open the back to expose the movement and read the number on the plate, near the ‘Waltham, Mass.’ signature. Do not use the number inside the case back — that is the case maker’s serial and it does not date the watch.

How old is my Waltham watch?

Enter the movement serial into the decoder above. Serials run from about 50 in 1852 to roughly 35 million in 1957, and each falls into a documented year block. The result is approximate: ledgers recorded when a batch started, and watches were often cased and sold one to two years later.

Does the serial number prove my Waltham is real?

No. The serial dates and identifies the movement, but it cannot prove authenticity on its own — serials were copied and parts were swapped for a century. Use it alongside the grade, case, dial, and an in-person inspection.

My serial is above 35 million — is that a Waltham?

Probably not an original American Waltham movement serial. American Waltham movement numbers stop around 35 million at the 1957 closure. A far higher number is usually the case serial or a later licensee product. Re-check that you are reading the movement plate.

Where do these dates come from?

From Waltham’s own factory production ledgers, preserved and published by collector references including the Pocket Watch Database and the NAWCC. The tables give the approximate start of each year’s serial block.

Is a modern ‘Waltham’ watch worth the same as an antique one?

They are entirely different. The original American Waltham (1852–1957) is a collectible antique. Later Swiss- or Asian-made watches carrying the licensed ‘Waltham’ name are unrelated products; the serial tables here do not apply and their value depends on their own model and condition.

Sources & full databases

The date table on this page was compiled and cross-checked against the published Waltham factory-ledger data. For the exact grade, model, run size, and per-serial detail of a specific watch, use a full searchable database:

Important note

Serial dating is one signal among several, and these dates are approximate. Combine the serial with the movement grade, case hallmarks, dial and hands, and overall condition when identifying a Waltham. For a valuable or uncertain vintage piece, an in-person inspection by a certified watchmaker is always the gold standard.

Identify your Waltham in 60 seconds

Upload photos of the movement, dial, and case for an AI read on model, era, and authenticity signals — a fast second opinion before you buy, sell, or service a vintage Waltham.

Start Scanning

For high-value or vintage pieces, pair your AI scan with an in-person inspection by a certified watchmaker.

Keep reading