Well, we do know the height of the average Na'vi male and female.

**Na’vi vary in size**, by region and genetic history. **Maximum recorded height is 3.9 meters**, with a mass of 290 kg, for a Na’vi male. Adult Na’vi males in the region of Australis surrounding Hell’s Gate, **average 3 meters in height** and 210 kg. **Females in this region average 2.8 meters**/190 kg.

Source

So, it's more or less math / guessing how tall babies, children and youngsters would be.

We also do know the following:

Data on lifespan is incomplete. It is generally accepted to be longer than human by approximately 30%, but **the rate of maturation is more rapid followed by a plateau of adulthood** without physical decline.

Source

So, babies, children, and youngsters grow fast until they reach adulthood.

My brain is only used to the metric system, so it kinda went blank when reading about

*feet* hrh.

Edit:

Ok, I tried to do some math, which I'm not good at, but yeah. If you find any mistakes, pls correct them.

I took the data from

Wikipedia and calculated the

**average male human height**.

The intersection of those 178 numbers is rounded

**172cm / 67,7 inches or 5,6 feet**.

According to

this source the average height of

**male human babies at birth is (rounded) 50cm, or 19,6 inches**, wich is 29% of those average 172cm.

6-month-old: 26,6 inches or 67,5cm, so 39%.

12-month-old: 29,8 inches or 75,7cm. 44%

2-year-old: 34,2 inches or 86,8cm. 50%.

3-year-old: 37,5 inches or 95,2cm. 55%.

5-year-old: 43,0 inches or 3,58 feet or 109,2cm. 63%.

10-year-old: 54,5 inches or 4,54 feet or 138,4cm. 80%.

15-year-old: 67,0 inches or 5,58 feet or 170,1cm. 98%.

According to Pandorapedia, let's assume that Na'vi are more or less fully grown at around 15 years old.

So... let's take these human numbers and apply them to the average Na'vi (Omatikaya) male height of 300cm or 3m (118,11 inches or 9,8 feet).

**A male Na'vi baby at birth would be 87cm or 34,25 inches or 2,6 feet (29% of 3m)**

6-month-old: 117cm or 1,17m or 46 inches or 3,8 feet (39% of 3m)

12-month-old: 132cm or 1,32m or 51,96 inches or 4,3 feet (44% of 3m)

2-year-old: 150cm or 1,50m or 59 inches or 4,9 feet (50% of 3m)

3-year-old: 165cm or 1,65m or 64,96 inches or 5,4 feet (55% of 3m)

5-year-old: 189cm or 1,89m or 74,4 inches or 6,2 feet (63% of 3m)

10-year-old: 240cm or 2,4m or 94,48 inches or 7,9 feet (80% of 3m)

15-year-old: 294cm or 2,94m or 115,74 inches or 9,6 feet (98% of 3m)So a 3 year old Na'vi would already be the same height as me (I'm 1,65m "tall") hrh ...