When is a Russian Blue fully grown?

Russian Blues reach their adult body size by approximately 12 months. Their coat continues to develop and reach full plushness over the following 6–12 months, but the cat's weight and skeletal frame are essentially mature at one year.

How much should a Russian Blue kitten weigh at 3 months?

A rough guideline is approximately 1–1.5 kg at 3 months, though individual variation is normal. Healthy kittens should be gaining weight consistently week to week. Any kitten that is losing weight or stagnating should be seen by a vet promptly.

Should my Russian Blue kitten look leaner than an adult?

Yes — kittens are naturally slimmer and less filled-out than adults. The lean, slightly elongated look of a young Russian Blue is normal and expected during growth. Concerns about underweight kittens are better assessed by tracking consistent weekly weight gain rather than judging appearance alone.

Russian Blue Growth Chart: What to Expect | PetCalculator

Russian Blues reach their full adult size by around 12 months and their full coat maturity a little later. This guide covers what healthy growth looks like from kittenhood through early adulthood for this graceful, moderate-sized breed.