Portafilter Basket Size Chart: 49 mm to 58 mm
Fifty eight millimetres is the commercial portafilter standard and the size with the complete accessory ecosystem. Home machines also use 49, 51, 52, 53, 54 and 57 mm, with 54 mm the common Breville size taking a 16 to 19 g double, against 14 to 22 g in a 58 mm double where 18 g is the reference dose.
Portafilter size is the outer diameter of the filter basket, in millimetres, and it decides which accessories you can ever buy. It is a compatibility standard rather than a quality rating: a well prepared puck makes good espresso at any of these diameters. What changes with size is how many baskets, tampers, distribution tools and screens exist for it, and 58 mm is the commercial standard where all of them are made first. Everything else is a smaller market attached to a smaller number of machines.
What is the portafilter size chart by machine?
Machine examples below come from the indexed machine list. Where a diameter has no machine in that list, the row says so rather than carrying an invented example, because a wrong compatibility claim costs a reader the price of an accessory that does not fit.
| Size | Example machines | Single dose | Double dose | Accessory ecosystem | Verdict |
|---|---|---|---|---|---|
| 49 mm | Flair 49 PRO, and the smaller Flair lever family | Not usually supplied | Roughly 12 to 18 g depending on the basket supplied | Lever-specific. Baskets and tampers come from the maker, almost nothing third party | A closed ecosystem attached to one product line |
| 51 mm | De'Longhi Stilosa, Dedica Arte, La Specialista Arte, La Specialista Maestro, La Pavoni Europiccola | 6 to 8 g | 12 to 14 g | Thin. A handful of tampers, some single wall basket conversions, few precision baskets | Common on compact machines. Expect to live with the baskets you were given |
| 52 mm | Wacaco Picopresso | Not supplied | 18 g | Almost entirely the manufacturer. A few generic 52 mm tampers exist | Unusually capable for its size, because it takes a normal 18 g dose |
| 53 mm | None of the machines indexed here. A legacy size on some older domestic Italian machines | About 7 to 9 g | About 14 to 16 g | Very thin, and easily confused with 54 mm when ordering | Check the actual basket with calipers before buying anything for it |
| 54 mm | Breville Bambino, Bambino Plus, Barista Express, Barista Express Impress, Barista Pro, Barista Touch, Infuser, Oracle Jet | 8 to 11 g | 16 to 19 g | Healthy. Precision baskets, calibrated tampers, dosing funnels, puck screens and bottomless portafilters are all made in 54 mm | The de facto home standard, driven almost entirely by one manufacturer |
| 57 mm | None of the machines indexed here. Found on some older Italian domestic and commercial-adjacent groups | About 7 to 10 g | About 14 to 18 g | Effectively none. A 58 mm accessory will not seat and a 54 mm one will not seal | Measure before buying. This is where mis-ordered tampers end up |
| 58 mm | Breville Dual Boiler, Oracle, Oracle Touch, Gaggia Classic Evo Pro, Gaggia E24, Rancilio Silvia, Silvia Pro X, Lelit Mara X, Lelit Bianca, Profitec GO, Pro 500, Pro 600, ECM Classika PID, Synchronika, Rocket Appartamento, La Marzocco Linea Mini, Nuova Simonelli Oscar II, Ascaso Dream PID, Diletta Bello+, Flair 58, Cafelat Robot, Decent DE1PRO | 7 to 12 g | 14 to 22 g, with 18 g the reference | Complete. Every precision basket, calibrated tamper, distribution tool, puck screen, funnel and bottomless portafilter is made in this size first | The commercial standard, and the reason 58 mm machines hold value |
The pattern in that table is the whole story. Twenty two of the machines in the machine index use 58 mm, eight use 54 mm, and every other diameter is attached to one manufacturer or one product line. That is not an accident of taste. Cafe machines have used 58 mm for decades, so basket makers, tamper makers and accessory brands tool for it first and treat everything else as an afterthought.
Why is 58 mm the commercial standard?
58 mm is the group head diameter used by commercial espresso machines, and the home market inherited it from the cafe market. A 58 mm basket holds a wider, shallower coffee bed than a 51 mm basket at the same dose, which means less depth for water to travel through and a lower pressure drop across the puck. In practice that makes an 18 g dose easy to extract evenly at 9 bar, which is exactly what commercial workflows need.
The commercial connection is also why 58 mm machines age well. A Gaggia Classic Evo Pro uses the same diameter group as machines built for professional service, so gaskets, screens, baskets and portafilters remain available and cheap, and the community around modifying it is enormous. A machine whose parts you can still buy in ten years is a different proposition from one whose manufacturer has moved on.
At the top of the home market, the Breville Dual Boiler is the usual first 58 mm machine for people coming from a 54 mm Breville, because it keeps a familiar interface while opening the full accessory market. Above it the E61 prosumer machines, and even manual devices such as the Flair 58 and the Cafelat Robot, all settled on the same diameter for the same reason: they can use parts that already exist.
Which accessories exist at each size?
This is the practical consequence of choosing a diameter. The matrix below is about availability, not quality.
| Accessory | 49 mm | 51 mm | 52 mm | 54 mm | 57 mm | 58 mm |
|---|---|---|---|---|---|---|
| Calibrated tampers | Maker only | Few | Few | Good | Almost none | Extensive |
| Precision baskets | Maker only | Rare | Maker only | Available | Almost none | Extensive |
| Bottomless portafilters | Built in | Rare | Built in | Available | Almost none | Extensive |
| Dosing funnels | Maker only | Few | Maker only | Good | Almost none | Extensive |
| Puck screens | Rare | Few | Rare | Good | Almost none | Extensive |
| Distribution and levelling tools | Rare | Few | Rare | Good | Almost none | Extensive |
At 58 mm the shopping list is straightforward: a spring-loaded tamper such as the Normcore V4 removes tamp pressure as a variable, a needle distribution tool breaks up the clumps that cause channelling, a magnetic dosing funnel keeps grounds inside the basket, a puck screen protects the shower screen, and a precision basket replaces the stamped one. All five exist in 54 mm too, in fewer variants. Below 54 mm you are largely buying whatever the machine's manufacturer decided to make.
Note the naming quirk: 58 mm accessories are usually labelled 58.5 mm. The basket interior is fractionally wider than the nominal diameter, so a true 58 mm tamper leaves an unsealed ring of coffee at the edge that water races through. The tamper roundup covers the sizing and the calibrated versus flat base question, and the puck prep guide covers the order these tools are used in.
What basket types exist within a size?
Diameter is only the fitting. Inside it, the basket type decides whether the grind setting matters at all.
| Basket type | How it works | Dose sensitivity | Verdict |
|---|---|---|---|
| Pressurised, dual wall | A second wall with one small exit hole creates artificial back pressure | Tolerates any dose and grind | Produces foam that looks like crema from stale or coarse coffee. It cannot be dialled in, because the basket, not the coffee, is setting the resistance |
| Single wall, stamped | Holes punched through one sheet of steel | Needs a dose within about 1 g of the rated size | The real starting point. Hole size and spacing vary, so flow can be slightly uneven across the bed |
| Single wall, precision | Laser cut holes with controlled diameter, spacing and total open area | Needs a dose within about 1 g of the rated size | More even flow and better repeatability. The cheapest meaningful upgrade on a machine that already grinds well |
| Ridgeless | No retaining ridge, so the basket lifts straight out | Same as its walled equivalent | Easier to clean and to knock out. Needs a spring clip or a snug fit so it stays put in the portafilter |
| VST and IMS style competition | Tight manufacturing tolerance on hole geometry and rated to a specific dose | Dose to the rating, plus or minus 0.5 g | Rewards an accurate scale and a consistent grinder, and punishes a sloppy dose more than a stamped basket does |
The pressurised basket is the single most common reason a new machine seems to make foam but not espresso. It generates back pressure mechanically through one small exit hole, so a coarse grind or stale pre-ground coffee still produces a thick head of bubbles. That is useful for the first week and a dead end afterwards, because no grind adjustment changes anything meaningful while the basket is doing the work. Once a burr grinder arrives, swap to a single wall basket in the same diameter. From that point the grind setting becomes the main control, which is what the grind size chart assumes you are working with.
How do you match dose to basket?
Dose to within about a gram of the basket rating. A basket rated at 18 g has an internal volume designed for roughly that mass of ground coffee at espresso fineness, with enough headroom left for the puck to swell when wet without touching the shower screen.
Under-dosing leaves a gap above the coffee bed. When the portafilter locks in, the puck sits low, water pools above it and finds the edges, and the result is a fast, sour, unevenly extracted shot that looks exactly like a coarse grind problem. Over-dosing does the opposite: the wet puck presses against the shower screen, which restricts flow, imprints the screen pattern into the spent puck and can eventually damage the screen or the gasket.
The spent puck is the diagnostic. Knock it out and look at it. A clean, dry, level disc with a faint screen imprint is correct. A soupy puck means the machine did not fully drain, which on a machine without a three-way solenoid valve is normal. A crater in the middle means channelling. A deep screen imprint across the whole surface means over-dosed. The extraction troubleshooting chart maps each of these to a single fix.
Does portafilter size matter when choosing a machine?
It matters more than most specification sheets suggest, and less than forum arguments claim. If you intend to buy accessories, tune puck prep and keep the machine for a decade, 58 mm is the size that keeps every option open and holds resale value. If you want a compact machine on a small counter and you are content with the baskets in the box, 54 mm or 51 mm is not a mistake. The De'Longhi Dedica Arte is 51 mm and only 5.9 inches wide, which is the right trade when counter space, not accessory choice, is the binding constraint.
Portable and manual devices are the clearest illustration. The Wacaco Picopresso uses a 52 mm naked portafilter with an 18 g basket, which is why it behaves like a real espresso maker rather than a travel novelty despite its size, while the Flair 49 PRO uses a 49 mm basket inside a closed lever ecosystem where the maker supplies everything. Both are good, and neither will ever share parts with anything else.
Before buying anything for a machine you already own, measure the basket with calipers rather than trusting a listing. The gap between 53, 54, 57 and 58 mm is small enough to look identical in a photograph and large enough that nothing seals. The machine index lists the published portafilter diameter for every machine covered here, and the buying guide puts portafilter size alongside boiler type as one of the two specifications that eliminate most of a shortlist.
Frequently asked questions
What is the standard portafilter size?
Fifty eight millimetres. It is the commercial standard used by cafe machines and by nearly every prosumer home machine, including the Breville Dual Boiler, Gaggia Classic Evo Pro, Rancilio Silvia, Lelit, Profitec, ECM and Rocket ranges. Because it is the commercial size, every precision basket, calibrated tamper, distribution tool, puck screen and bottomless portafilter is made in 58 mm first, and often only in 58 mm.
Why are tampers sold as 58.5 mm rather than 58 mm?
Because a 58 mm portafilter does not have a 58 mm basket interior. The basket walls taper and the usable inner diameter at the coffee surface is slightly wider than the nominal figure, so a true 58 mm tamper leaves an unsealed ring of grounds at the edge. Tampers at 58.5 mm close that gap without binding. If your tamp leaves a visible rim of loose coffee, the tamper is undersized.
What is the difference between a 54 mm and a 58 mm machine?
Mostly accessories and resale value rather than shot quality. A well prepared 18 g puck in a 54 mm basket can produce excellent espresso, and Breville has sold enough 54 mm machines that a reasonable accessory market exists. The 58 mm ecosystem is simply larger and cheaper, since it is shared with commercial equipment, and 58 mm machines tend to hold value better because their parts remain available for decades.
How much coffee goes in a double basket?
Between 14 and 22 grams in 58 mm, with 18 grams the reference dose that nearly all published recipes assume. A 54 mm double normally takes 16 to 19 grams, a 51 mm double 12 to 14 grams, and the 52 mm Picopresso basket is rated at 18 grams. Dose to within about a gram of the basket rating: under-filling leaves headroom that water channels through, and over-filling presses the puck into the shower screen.
Can I put a different size basket in my portafilter?
Only within the same diameter. Baskets are held by a spring clip sized to the portafilter, so a 54 mm basket will not seat in a 58 mm portafilter and a 58 mm basket will not fit a 54 mm one. What you can change within a size is depth and rating, for example swapping a 14 gram basket for an 18 gram one, provided the deeper puck still clears the shower screen when the portafilter is locked in.
Should I replace the pressurised basket that came with my machine?
Yes, once you have a burr grinder. A pressurised or dual wall basket adds artificial back pressure through a single small exit hole, which produces foam from almost any coffee, including stale pre-ground. It also makes dialling in impossible, because the basket rather than the coffee is setting the resistance. Swap to a single wall basket in the same diameter and the grind setting starts to matter, which is the point.
How we choose: we compare published manufacturer specifications, verified owner reviews and published barista guidance. We do not test gear in person. Espresso machines run mains electricity, pressurised water and steam above boiling point, so follow your manufacturer's manual and leave electrical or boiler work to a qualified technician. Everything here is researched guidance, not professional advice.