So I was sitting in my garage yesterday trying to mount this damn bracket, right? Pulled out my trusty metric tape measure since everything else here works in millimeters. The hole spacing on the bracket read exactly 32.5 mm. But wouldn’t ya know it – my drill bit case only shows inch sizes. Typical.

The Stupid Math Struggle
Now I ain’t no wizard with numbers, but I remembered something from way back – something about 25 millimeters making about an inch? Grabbed a scrap paper and did this:
- Just shoved my calculator app open. Typed 32.5 divided by 25. Got 1.3. “Alright,” I thought, “that’s 1.3 inches then?” Felt kinda fishy though. Didn’t seem precise enough.
Turned out I messed up big time. Found this faded conversion chart stuck under my toolbox later. Saw that 1 inch equals exactly 25.4 millimeters, not 25. Felt like an idiot. No wonder things never fit when I eyeballed it.
Actually Doing It Properly
Punched in 32.5 divided by 25.4 this time. Here’s the raw number I got:
- 32.5 / 25.4 = 1.279527559… That ugly long decimal stared back at me.
For real-world use though? Ain’t nobody marking sixteenths of an inch against a tape measure gonna read that mess. Needed something practical. Rounded it to three places because that’s all my old eyes could handle:
- Becomes 1.280 inches. But even that felt fiddly.
What You Actually Need To Know
Screw those endless decimals. In the real world cutting wood or drilling metal, you work with fractions. Used an online decimal-to-fraction thingy (cause my brain switched off after 3pm).

- 1.2795 inches is damn close to 1 and 7/32 inches. Checked it: 1 inch = 25.4mm, 7/32 inch = about 5.556mm. Added them together: 25.4 + 5.556 = about 30.956mm. That was LESS than 32.5mm. Nope.
- Tried something bigger: 1 and 9/32 inches. 1 inch = 25.4mm, 9/32 inch ≈ 7.144mm. Added ’em: 25.4 + 7.144 = 32.544mm. Now THAT’S decently close to our 32.5mm. Good enough for using my chunky drill bits!
So why do I need this? Cause last year I drilled a shelf bracket hole wrong by mixing up millimeters and inches. Whole thing tilted sideways like the Leaning Tower of Pisa. Wife mocked me for a week. Never again. Now I keep a dirty little cheat sheet stuck to the garage wall:
~32.5 mm ≈ 1 and 9/32 inches. Ugly fraction? Maybe. But it keeps the shelves straight.