How to Date a Waltham Watch by Its Serial Number
The short answerFind the serial number engraved on the movement, not the case, and look it up on Waltham's production chart. Our tonneau's serial, 25,822,271, falls between the 1926 and 1927 starting numbers, so its movement was made around 1926 or 1927.
Turn over an old Waltham, open the caseback, and you'll find a long number engraved on the movement. That number is the closest thing the watch has to a birth certificate.
The Waltham Watch Company, based in Waltham, Massachusetts, numbered its movements in one long run starting in 1852. Because the count only ever went up, collectors can line a serial number up against a published chart and get a good idea of when the movement was made.
Where to look
The serial you want is on the movement itself, not the case. The two are easy to confuse, because the case usually has its own number stamped inside the back. Many cases were made by separate companies like Keystone, Fahys or Dueber, so the case number belongs to them and won't match. That's normal, and it doesn't mean anything is wrong.
Reading the chart
Here is how the 1920s fall on the standard chart, by the serial number each year starts at:
- 1924: 24,550,000
- 1925: 24,800,000
- 1926: 25,200,000
- 1927: 26,100,000
- 1928: 26,400,000
- 1929: 26,900,000
- 1930: 27,100,000
Treat it as a close estimate rather than an exact date. Serials weren't always used in strict order, and a watch could sit in a jeweler's case for a year or two before anyone bought it.
An example from our shelves
Our Waltham Art Deco tonneau carries serial 25822271. That number falls after the 1926 start of 25,200,000 and before the 1927 start of 26,100,000, so the movement was made around 1926 or 1927. It fits the watch around it, too: the tonneau case, green Arabic numerals and small seconds dial all look right for the period.
If you'd rather not count digits, the Pocket Watch Database lets you type in a Waltham serial and see the estimated year and the movement grade. It's a good second opinion.
Why it matters
A date tells you whether the parts belong together. If a seller calls a watch 1950s and the movement dates to 1918, something has been swapped, or the listing is wrong. When we list a Waltham, we give the serial and the date it points to, so you can check our work.
See every watch we have right now.
Questions we get
Why doesn't the number on the case match the movement?
Many Waltham cases were made by separate companies, such as Keystone, Fahys or Dueber, and carry their own numbers. A mismatch is normal.
How exact is a date from the serial number?
It's a close estimate. Serials weren't always used in strict order, and a watch could sit in a jeweler's case for a year or two before it sold.
Can I look up a Waltham serial online?
Yes. The Pocket Watch Database lets you enter a serial and see the estimated year and the movement grade.
