To measure a watch case with a ruler, you need to determine its diameter in millimeters by measuring across the widest part of the case, specifically excluding the crown.
Step-by-Step Guide to Measuring Your Watch Case
Measuring a watch case correctly ensures you know its true size, which is important for fit and aesthetics. The standard measurement for watch case size is the diameter in millimeters.
Getting Started
Before you begin, ensure you have a ruler or measuring tape that clearly shows millimeter (mm) markings.
The Measurement Process
Follow these simple steps to measure your watch case:
- Position the Watch: Place the watch face up on a flat surface.
- Place the Ruler: Lay your ruler flat across the watch case.
- Find the Widest Point: Identify the widest horizontal point of the watch case. This is typically straight across the middle of the case.
- Align and Measure: Align the zero mark of your ruler with the outer edge of the watch case at the widest point on one side.
- Read the Measurement: Read the measurement at the corresponding outer edge on the opposite side of the watch case.
- Exclude the Crown: Crucially, you must measure the diameter in mm from the outer edges at the widest point of the watch, not including the crown. Make sure your measurement runs across the case body only and does not extend into the crown or crown guards.
- Note the Size: The number you read on the ruler in millimeters is the case size or diameter.
Important Tips for Accurate Measurement
- Use Millimeters: Always use the millimeter (mm) scale on your ruler for precision.
- Exclude Protrusions: Remember not including the crown or any other pushers when measuring the diameter.
- Widest Point: Ensure you are measuring across the widest point of the case body.
- Outer Edge to Outer Edge: Measure from the absolute outer edges of the case itself.
Example Measurement
Let's say you measure a watch and the ruler shows the distance from one outer edge to the other outer edge at the widest point (excluding the crown) is 40 units on the millimeter scale.
| Measurement Point 1 | Measurement Point 2 | What to Exclude? | Result (Diameter) |
|---|---|---|---|
| Outer Case Edge | Opposite Outer Case Edge | Crown, Pushers | 40 mm |
By following these steps, you can accurately measure your watch case size using a standard ruler.
