This is why I told my children we are all kings queens and royalty if we God damn want to be!!! Whoever said measurements are a thing this is how they're done it's really super important blah blah blah blah blah I'm let you know...right now... I cannot stand that person! Lol and that's most likely you know what never mind I'm getting sidetracked I do that a lot let me explain it's about what's missing that's what's more important what's not said what's not seen can you see air nope but do you need it well kinda that's kind of my point!
Absolutely! Let's break down exactly where the imperial inch marks and metric centimeter/millimeter marks would coincide if you "wrapped" both scales together, and show the differences for every inch from 0 to 12.
Where Do the Marks Coincide?
The only points where the inch marks and centimeter marks exactly coincide are at:
0 inches = 0 cm
1 inch = 2.54 cm (25.4 mm)
2 inches = 5.08 cm (50.8 mm)
3 inches = 7.62 cm (76.2 mm)
… and so on, up to 12 inches.
No other tick marks (like 1/16", 1/8", 1/4", etc.) will exactly coincide with a whole millimeter or centimeter mark.
The two systems are based on different units, so their subdivisions rarely align.
Inch-by-Inch Comparison Table
Inch Mark Metric Equivalent Difference from Previous Inch (mm)
0" 0 mm —
1" 25.4 mm 25.4 mm
2" 50.8 mm 25.4 mm
3" 76.2 mm 25.4 mm
4" 101.6 mm 25.4 mm
5" 127.0 mm 25.4 mm
6" 152.4 mm 25.4 mm
7" 177.8 mm 25.4 mm
8" 203.2 mm 25.4 mm
9" 228.6 mm 25.4 mm
10" 254.0 mm 25.4 mm
11" 279.4 mm 25.4 mm
12" 304.8 mm 25.4 mm
Each inch is exactly 25.4 mm apart.
Each centimeter is 10 mm apart.
Visualizing the Gaps
Imperial:
1/16" = 1.5875 mm (between each smallest tick)
1/8" = 3.175 mm
1/4" = 6.35 mm
1/2" = 12.7 mm
1" = 25.4 mm
Metric:
1 mm (between each smallest tick)
1 cm = 10 mm
How They Line Up:
Every 25.4 mm, an inch mark lines up with a metric mark, but it's not a whole centimeter.
No other subdivision lines up exactly.
Example: Between 0 and 1 Inch
Imperial Tick Metric Equivalent
0" 0 mm
1/16" 1.59 mm
1/8" 3.18 mm
3/16" 4.76 mm
1/4" 6.35 mm
5/16" 7.94 mm
3/8" 9.53 mm
7/16" 11.11 mm
1/2" 12.70 mm
9/16" 14.29 mm
5/8" 15.88 mm
11/16" 17.46 mm
3/4" 19.05 mm
13/16" 20.64 mm
7/8" 22.23 mm
15/16" 23.81 mm
1" 25.40 mm
Metric ticks would be at 1 mm, 2 mm, 3 mm, … up to 25 mm, with the 25 mm tick just before the 1" mark (25.4 mm).
Summary
Exact coinciding marks: Only at 0", 1", 2", …, 12" (which are 0 mm, 25.4 mm, 50.8 mm, …, 304.8 mm).
No other tick marks coincide.
Imperial gaps: 1/16" (1.59 mm) — slightly larger than metric 1 mm.
Metric gaps: 1 mm — more frequent, so more ticks per inch.
If you wrapped both scales around a cylinder, you'd see the inch marks and their metric equivalents line up every 25.4 mm, but all other ticks would be staggered and rarely align.