Top Time B31

Ref. AB3113A71C2X1

Case diameter: 38 mm; Manufacturer spec
Lug-to-lug: 45.8 mm; Measured in a published review
Thickness: 10.3 mm; Manufacturer spec
Lug width: 20 mm; Manufacturer spec

Retail price $5,850 (US, Oct 2026)

Your wristIdeal fit

Wrist flat: 55.1 mmLug-to-lug: 45.8 mm

How the Top Time B31 wears

Its lugs add 7.8 mm to the 38 mm case, close to the 7 mm typical across the almanac, so its diameter is a fair guide to how it wears.

On our fit model it sits best on wrists from 6.5" to 7.75" (16.5–19.7 cm); below 6.5" the lugs start to reach the edge of the wrist.

At 10.3 mm thick it is slimmer than 80% of the 101 other everyday watches we've measured, so it slides under a cuff more easily than most.

Its 20 mm lug width is one of the most common strap sizes; 156 other watches here share it, so aftermarket straps are easy to find.

Will the Top Time B31 fit your wrist?

With a 45.8 mm lug-to-lug, here is how it wears across common wrist sizes. We estimate the flat top of each wrist from its circumference; measure yours for a closer answer in the fit finder.

Wrist	Flat width (est.)	Fit
6"	47.2 mm	Snug, lugs near the edge
6.5"	51.2 mm	Ideal fit
7"	55.1 mm	Ideal fit
7.5"	59.1 mm	Ideal fit
8"	63 mm	Wears small

Specifications

Reference: AB3113A71C2X1
Collection: Top Time
Status: In production
Case material: stainless steel
Crystal: sapphire
Water resistance: 100 m
Bezel: fixed
Strap / bracelet: blue calfskin strap
Weight: 66 g
Style: Everyday, Sport

Movement

Caliber: Breitling B31
Type: automatic
Power reserve: 78 hours
Frequency: 28,800 vph (4 Hz)
Accuracy: COSC-certified chronometer

Takes 20 mm straps. See other 20 mm watches and straps.

Watches that wear the same size

Other watches within 1.5 mm of its lug-to-lug.

Same 20 mm lug width

All 20 mm watches

These take the same straps as the Top Time B31.