Skate Sizing

Choosing the correct skate size is a very important task and usually even more important than choosing the skates model! All high-quality skates will have a break in period and would adjust over time to the skater’s feet. Some will take longer and some shorter, but while you want to have a comfortable ride you do not want to have the skates too loose… The correct fit will determine much more than just the comfort - it will define how much control, power transfer, and agility you would have while skating, and even would affect the balance.

While various skating styles and skaters themselves have different preferences, below are the general instructions of how to determine the perfect fit for your new skates.


Most of inline and roller skates are manufactured and sold in European sizes (EU), so your US / UK sizing could be a wrong idea to use due to the conversion inaccuracies. Furthermore, even if you know your European sizing, every shoe and skate manufacturer has a slightly different fit and sizing, therefore your standard shoe size might not assure a perfect fit but that is the best way to estimate your skate size. In any case, the inline and roller skate size should be either equal to your shoe size or no more than one size up or down from it.
Based on our experience, the best way to determine your skate size is to take a look at your current pair of skates and/or running shoe labels for MM / CM / MP / MONDO numbers. These numbers are indicating the maximum foot length that will fit into the pair, while MM shows the measurement in millimeters and CM/MP/MONDO is centimeters. Having these numbers along with the EU sizes from these shoes, you will be able to determine the size of the skates that you need by looking into brand or model specific sizing chart (usually located in the Sizing tab under the skates photos or as one of the product photos). If cannot be located, please send us an inquiry and we gladly will help you out!
Important: Many shops are recommending measuring your feet to determine your skate size, but we have found that this leads to too many mistakes and do not recommend that. If after following the instructions above you are finding yourself stuck in between two sizes, you could measure your feet according to the directions below. In this case, your shoe size is still the defining factor, so if the measurement is showing more than one size up or down, something is wrong with the measurement! If your foot is wider than average, please go one size up. Usually, Seba, FR, and Adapt skates fit wider than average, Powerslide and K2 average, Flying Eagle and Rollerblade average to narrow...

Still, want to measure your feet? Here is how to do it:

You’ll need paper, pen, a flat wall and, if possible, a buddy to help. It’s best to measure your feet later in the day after you have been on them for a few hours to account for swelling.
Find a hard floor with a flat wall. Tape a piece of paper down so that it touches the wall. Stand on the paper in bare feet, with your heel just touching the wall.
Have your friend take a book and place it so that it just touches the tip of your longest toe. Mark the spot where the book meets your toe. Do this with both feet and use the larger of the two measurements. Measure your foot length in millimeters, if possible. If you measure in inches, be sure to measure in 16ths of an inch.
Choose your size from the manufacturers sizing chart. The “Max Foot Length” is the longest foot measurement that will fit into that size. The US Men’s column lists the sizes found on the box.


Our sizing advice is targeted to a freestyle or dance skater who wants a very snug fit in their skate to enjoy maximum control. Our instructions will give a fit that prioritizes control over comfort. If comfort is a higher priority, or if you have an especially wide or oddly shaped foot, you may do well to choose a slightly larger size. If you are near the boundary between two sizes, you would probably be better off to go with the larger size in case you prefer comfort over control.
Notes about Width
In general, the Plastic Boot skates with a built-in liner have a narrower fit through the foot, while the boots with a removable liner and soft boots have a somewhat wider fit. The Carbon is a bit wider through the toe box than the plastic boot skates because the carbon fiber boot has less flex. As a rule of thumb, skates with built-in liners and "regular" liners will have less adjustment room.
We gladly will guide you in case you have any further questions. Email us at [email protected]

To help you better, please include all the sizing information off one or two pairs of skates or running shoes that you currently have including EU/US/UK/MP/CM/MM/MONDO, etc...

Powerslide Swell City Grey 125 Aerofit Inline Skates
USD$430.00 USD$329.79 Select options

Powerslide Swell City Grey 125 Aerofit Inline Skates



Powerslide Swell City Grey 125 Pump Inline Skates. The Swell gets better with each generation. This time with completely reworked boots and technology.

The Swell City uses short frames (compared to the Swell Road) to allow for shorter strides and quicker changes in direction (maneuverability). MyFit Aerofit Technology (Pump System) adapts the inner boot to your specific foot shape in seconds, reducing weight and removing pressure points to boost your performance. The new ventilated upper is made out of Powerknit material with TPU welded reinforcements to fit seamlessly.

TRINITY X refers to added lateral adjustment than previous versions (3 fixation points lower center of gravity, add stability, and increase power at push-off). Equipped with waxed laces, magnesium cast frames (light to reduce fatigue), Undercover 125mm wheels, and Wicked ABEC 9 bearings.

Short 10″ frames keep the skater in an aggressive, forward-leaning stance. Powerslide refers to the Swell City as ‘urban fitness skate’ as it comes out of the box, but the Swell boot is compatible with any trinity mount frame from Powerslide should you want to change wheel configurations or frame length later on.

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Perfect for Fitness skating

  • Shell: Glass-Fiber Reinforced plastic (GFRP) – GFK
  • Upper: Powerknit with polyurethane thermo-welding
  • Closures: Micro-adjustable force ratchet, Middle Velcro 45° Strap, and Laces
  • Cuff: Special flex nylon
  • Liners: built-in with MYFIT Recall memory fit and MYFIT Aerofit
  • Insole: MYFIT skatesole EVA
  • Frame: Elite Magnesium Cast CNC 255mm Trinity Frame 12,5\”
  • Frame Mount: Trinity with Lower Center Of Gravity
  • Wheels: Undercover \”raw white\” 125mm/85a
  • Bearings: Wicked ABEC9
  • Brake: Powerslide HABS (height adjustable brake system).
  • Skate Height: 33,0cm (size 41)
  • Weight:  3380g (size 41)



Additional information

Weight4.5 kg

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Wheel Size (mm)

Boot Durability

Boots Comfort

Boots Control

Boots Fit

Setup Speed

Recommended Skill Level

Boot Ventilation


PS Swell Sizing Chart

Accordingly to Powerslide, the Swell boots are fitting fairly true to the shoe size. Based on our experience, these skates are narrower than usual and somewhat tight in the cuff area.

Please note: your shoe size is the defining factor! Almost never, the size of the inline skates will be smaller than your shoe size. If your foot is wider than average, please go one size up than your shoe size. As a general rule, Powerslide fits average in width.If you want to use the foot length information to narrow the sizing down, the best way is to get that information from your running/sports shoe sizing label. Almost always they will have one of the following: MP/MONDO/CM – length in centimeters or MM – length in millimeters.

  • The US shoe sizes mentioned in the sizing table are US men.