Caliber
Caliber is a term used to describe the internal diameter of a cylindrical object, most commonly the inside diameter of a gun barrel or firearm bore. It is typically measured in inches or millimeters.
In firearms, caliber indicates the diameter of the bullet or projectile that can be fired from the barrel (e.g., a .45 caliber means the barrel’s internal diameter is 0.45 inches).
In other contexts, such as engineering or piping, caliber can refer more generally to the diameter or thickness of tubes or cylindrical objects.
Key points:
Caliber = internal diameter of a barrel or tube
Measured in inches or millimeters
Important for firearm specifications and ammunition compatibility
Also used in engineering and manufacturing
Caliber is crucial for matching ammunition to firearms and for defining performance characteristics like velocity and accuracy.
Perch
A perch is an old unit of length that is synonymous with the rod or pole, commonly used in land measurement and surveying. It measures 16.5 feet, 5.5 yards, or approximately 5.0292 meters.
The perch was widely used in England and later in the United States for measuring plots of land, especially before the widespread adoption of the metric system. It was also used to describe area when squared (square perch).
Key points:
1 perch = 16.5 feet
1 perch = 5.5 yards
1 perch ≈ 5.0292 meters
4 perches = 1 chain
40 perches = 1 furlong
While largely obsolete today, the term perch still appears in historical land deeds, legal documents, and some traditional surveying contexts.
No conversions available for length.