Timber (Lumber) sizes metric compared against dimensional

The thing that I have found a bit challenging when determining which timber to use has been the sizing.

Below is what I have been substituting for the dimensional lumber sizes noted in plans, I am live in Adelaide, Australia. I just wanted to run these past others here to see what they thought, are these roughly the timber sizes you have been using. It would be comforting to know I have been on the right track.

1x4 = 19mm x 90mm

1x5 = 19mm x 120mm

1x6 = 19mm x 140mm

1x8 = 19mm x 190mm

1x10 = 19mm x 240mm

2x4 = 35mm x 90mm

2x5 = 35mm x 120mm

2x6 = 35mm x 140mm

2x8 = 35mm x 190mm

2x10 = 35mm x 240mm

Would love others input.

Cheers

Deanna