Espresso portafilter sizes: 51mm vs 54mm vs 58mm
Your machine's group size decides which baskets, tampers and portafilters fit. Here's how the three common sizes compare - and which machines use each.
Drawn to scale. A 58mm group is about 14% wider across than a 51mm. The gap is small but absolute - a 54mm basket will not seat or seal in a 58mm group, and vice-versa. There is no adapter; size must match (tampers excepted: buy 1mm under).
51mm Budget entry
De'Longhi Dedica
Fits: Basic bottomless portafilters and a few baskets.
Thinnest aftermarket - keep it simple.
54mm Breville standard
Breville Bambino Plus · Breville Bambino · Breville Barista Express
Fits: Bottomless PFs, single-wall & precision baskets, tampers (53mm), distributors, shower screens.
Deep, beginner-friendly range.
58mm Commercial standard
Gaggia Classic Evo Pro
Fits: VST/IMS precision baskets, bottomless PFs, tampers (58mm), PID & OPV mods.
Widest selection - the upgrade engine.
The one rule: match the size to your group head. Baskets, screens and portafilters must be exact; tampers and distributors go 1mm under (a 53mm tamper for a 54mm Breville). The wrong size will not seat or seal.
Sources (verified 2026): Barista-Essentials portafilter size chart · Espresso Setup Builder · manufacturer specs (Breville, Gaggia, De'Longhi). We have not physically tested every pairing; verify your group size before buying.