1. Take your old T-shirt
  2. Take measurements as in the photo: under the sleeves from seam to seam and from the neck to the bottom
  3. Compare with our size chart (Width/Length):
    1. XS 45 62
      S 49 67
      M 53 70
      L 57 75
      XL 60 78
      2XL 62 81

All dimensions are in "cm"