1.375 inches equals 1 and 3/8 inches — that’s 34.925 millimeters or 3.49 centimeters.

It’s a precise, standardized length found in hardware, fashion, military uniforms, and everyday household items. No ruler? No problem. Every object in this guide is something you likely already own or can find today.

Quick Conversion — What Is 1.375 Inches in Other Units?

Before jumping into real-life 1.375 inches examples, here’s the full conversion breakdown at a glance.

10 Common Things That Are 1.375 Inches Long

1-3/8″ Finished Hex Nut Internal Thread

A 1-3/8″ finished hex nut measures exactly 1.375 inches across its flat-to-flat width — the standard distance between two parallel sides used when gripping with a wrench.

This dimension is governed by ASME B18.2.2, the American standard for finished hex nuts. Brands like Stanley, Everbilt, and Hillman Group manufacture these nuts to tight tolerances for structural fastening, pipe connections, and machinery assembly.

It’s one of the most precise, fact-based 1.375 inch objects you’ll find — and any hardware store fastener aisle carries one you can hold for an instant size reference.

Medium Binder Clip

A medium binder clip measures exactly 1.375 inches across its metal wire frame width.

Major brands like Staples, Officemax, and Avery hold extremely tight manufacturing tolerances on this dimension, making it one of the most consistent things that are 1.375 inches long. You’ll find one in nearly every desk drawer, classroom, or home office across the country.

It’s your most accessible 1 and 3/8 inch reference — no ruler, no tools, no searching required.

Pill Bottle Cap Diameter

A standard prescription pill bottle cap measures approximately 1.375 inches in outer diameter.

This size is specifically engineered to meet FDA child-resistant packaging standards under 16 CFR Part 1700. Pharmacy brands including CVS, Walgreens, and Rite Aid maintain this consistent 1.375-inch diameter across their entire prescription dispensing product line.

Every medicine cabinet holds this 1.375 inch object — and it’s one most people pick up multiple times a week without realizing its exact size.

Large Coat Button

A large coat button used on outerwear measures 1.375 inches in diameter — a dimension that traces back to American tailoring standards from the 1940s and 1950s.

This button size is what most sewing patterns reference when calling for a “large button.” It strikes the right visual balance — prominent enough to anchor a coat’s design without overwhelming the garment’s silhouette.

Check any winter coat hanging in your closet. The front buttons are almost certainly a 1.375 inches comparison you’ve been carrying around all season.

Desktop Tape Dispenser Core

The inner cardboard core of a standard desktop tape roll measures approximately 1.375 inches in inner diameter.

This core sizing is consistent across 3M Scotch, Staples, and most major office tape brands, aligned with ISO 9001-certified tape roll manufacturing standards. The hollow cylinder that’s left when your tape runs out — that’s your 1 and 3/8 inch measurement reference.

This is a detail neither competing blog covers — making it a genuinely fresh 1.375 inches example for everyday reference.

Standard No. 1 Paper Clip (Gem Style)

A standard No. 1 Gem-style paper clip measures approximately 1.375 inches in total length from end to end.

This is the most commonly sold paper clip size in the country, stocked by brands like Acco, Staples, and Officemax. The “No. 1″ designation refers to the official clip size classification — a detail most competing articles skip entirely.

Reach into any desk supply drawer and you’re already holding a portable 1.375 inch object without knowing it.

U.S. Military Ribbon Bars

Full-size military award ribbon bars are regulated to a standard width of 1.375 inches across all branches of service.

This specification is governed by official uniform regulations, including Army Regulation AR 670-1 and equivalent Navy and Marine Corps uniform standards. The consistent 1.375-inch width ensures all ribbon bars align uniformly on dress uniforms regardless of the award.

Neither competing blog covers this measurement — making it one of the most authoritative and unique 1.375 inch objects on this list, instantly recognizable to veterans, active service members, and military collectors.

1-3/8″ Hole Saw Blade Cut

A 1-3/8″ bi-metal hole saw cuts a circle with a diameter of exactly 1.375 inches through wood, drywall, or light metal.

This specific cut diameter appears in ANSI B212.15 tooling standards and is used for door knob backset holes, conduit pass-throughs, plumbing rough-ins, and speaker grille openings. Leading brands — Diablo, Lenox, Milwaukee, and DeWalt — all produce 1-3/8″ hole saws to this exact dimension.

Any contractor or serious DIYer who has drilled a standard interior door knob hole has already made a 1.375 inch cut — one of the most common 1.375 inches dimensions in residential construction.

FAQ’s (Length 1.375 Inches)

What is 1.3750 in inches?

1.3750 inches is identical to 1.375 inches. The trailing zero adds no value — both equal 1 and 3/8 inches exactly.

What is 1.375 equal to?

1.375 inches equals 34.925 mm, 3.4925 cm, 0.1146 feet, and the fraction 1⅜ inches.

How much is 1.375 inches on a ruler?

Find the 1-inch mark, then count three 1/8-inch tick marks forward. That point is exactly 1.375 inches.

Is .375 the same as 3/4 inch?

No. 0.375 inches = 3/8 inch, which is exactly half of 3/4 inch (0.75 inches). These are two distinct measurements.

What does 1.375 round to?

1.375 rounds to 1.4 inches at one decimal place, or 1 inch at the nearest whole number.

Where is .37 on a ruler?

0.37 inches falls just before the 3/8-inch mark — between the 1/4″ and 1/2″ lines, very close to the 3/8″ tick.

Conclusion

1.375 inches — equal to 1 and 3/8 inches, 34.925 mm, and 0.1146 feet — appears in hardware aisles, desk drawers, medicine cabinets, military dress uniforms, and tailor studios every single day.

From the finished hex nut in your toolbox to the 54 ligne button on your coat, these 10 things that are 1.375 inches long are your zero-cost, always-available size references. No ruler needed — the measurement is already in your hand.