Willi Footwear

Size Guide



The bases will vary a few millimetres. It is best to measure your foot or an old pair, from the centre of the heel, to the top of your big toe.

Please always check your size before ordering as you will incur postage fees should you need to swap for a different size.


Do you have really narrow or really wide feet?
Smaller or larger sized straps can be added to different sized bases. This means you can customise your fit to perfection!
Slim straps can be added to the corresponding Mens / Unisex base and vice versa.
Get in touch if you need help choosing your size.


The Boomerangz size range is based on the MENS US size range. Although they are UNISEX (it says UNISEX on the base) – This means that if you are ordering a ladies slim style and you are normally a 9, you will need to order a 7/8 instead. If you are normally a 7/8, you will need to order a 6 and so on… best to measure your foot or an old pair and use the sizing charts provided¬† ūüôā




  1. Click on the link below of your desired size
  2. The PDF will open in a new window
  3. Click FILE then click PRINT
  4. Make sure PAGE SCALING is set to NONE
  5. Place your foot in the outline to see if that is your correct size
  • US Slim 4/5 — Aus Slim 4/5 — 235mm L — 94mm W
  • US Slim 6 — Aus Slim 6 — 247mm L — 95mm W
  • US Slim 7/8 — Aus Slim 7/8 — 260mm L — 98mm W
  • US Slim 9 — Aus Slim 9 — 272mm L — 100mm W
  • US Slim 10/11 — Aus Slim 10/11 — 286mm L — 103mm W
  • US Regular 7/8 — Aus Reg / Unisex¬† 7/8 — 260mm L — 100mm W
  • US Regular 9 — Aus Reg / Unisex¬† 9 — 272mm L — 102mm W
  • US Regular 10/11 — Aus Reg / Unisex¬† 10/11 — 286mm L — 107mm W
  • US Regular 12 — Aus Reg / Unisex¬† 12 — 298mm L — 109mm W
  • US Regular 13/14 — Aus Reg / Unisex¬† 13/14 — 308mm L — 113mm W