So, calculations regarding Amazon sizes vs. our/Littles' sizes. I will use my own height - 5 foot, 9 inches - to demonstrate.
First off, the Amazon size that I generally see in most stories - their 10 feet tall is our 6 feet tall. With this:
To find out how small you appear to an Amazon, multiply your height by 0.6, or 3/5; I'm 5'9", so I would be the equiv of ~41.4 inches (~3'5.4"), the size of an Amazon 4-year-old or so
To find out how tall you would be as an Amazon, multiply your height by 5/3, or 1.6 (well, actually by 1.666666...); I would be 115 inches (9'7")
Second, the Amazon size seen in Superfunnel's works - Amazons' 15 feet in height is our 6 feet. With this:
To find out how small you appear to a Superfunnel Amazon, multiply your height by 0.4, or 2/5; I would be equiv to 27.6 inches (2'3.6") - about the size of an Amazon 8-month-old
To find out how tall you would be as an SF Amazon, multiply your height by 5/2, or 2.5; I would be 172.5 in. (14'4.5")
Lastly, if you wanna go for a point in-between those two scales, then (10 & 15, 11 & 14, 12 & 13...) their 12.5 feet is our 6. With this:
To find out how small you appear to this scale of Amazon, multiply your height by 12/25 (0.48); I would be equiv to 33.12 in. (2'9.12") - around the size of an Amazon 20-month-old
To find out how tall you would be as an Amazon, multiply your height by 25/12 (2.083333...); I would be 143 & 3/4 in. (11' 11.75")
Fair warning that math is NOT my strong suit; if anybody more math-inclined than me wants to correct any errors I've made, please feel free to.