Guys found some awesome information on a North American site, which gauges and estimates the weight of a Trout from its measurements, similar to how the SASAA tables work, I adapted it and converted it so I thought I would share with you guys, maybe it will help
this table is generally more accurate for "wild" Rainbow Trout, but give or take a few 100 grams and this can be applied to stocked fish, and their weight is very similar to Brown Trout, generally at each length a Brown Trout will be 10 to 60 grams heavier. There is also a lot of discrepancies below, this should be used as a general guideline and not as absolute accurate. For example, I have seen a 72cm Trout that only weighed 4kgs, and I have caught a 39cm fish that weighed slightly over 1kg.
30cm - 350 grams
31cm - 400 grams
32cm - 450 grams
33cm - 500 grams
34cm - 550 grams
35cm - 600 grams
36cm - 650 grams
37cm - 700 grams
38cm - 750 grams
39cm - 800 grams
40cm - 850 grams
41cm - 900 grams
42cm - 1kg
43cm - 1.1kg
44cm - 1.15kg
45cm - 1.2kg
46cm - 1.3kg
47cm - 1.4kg
48cm - 1.5kg
49cm - 1.6kg
50cm - 1.7kg
51cm - 1.8kg
52cm - 1.9kg
53cm - 2kg
54cm - 2.15kg
55cm - 2.3kg
56cm - 2.4kg
57cm - 2.5kg
58cm - 2.65kg
59cm - 2.8kg
60cm - 2.95kg
61cm - 3.1kg
62cm - 3.25kg
63cm - 3.4kg
64cm - 3.55kg
65cm - 3.7kg
66cm - 3.85kg
67cm - 4kg
