Anacondas are among the largest snakes on Earth, with big females reaching close to 9 meters (about 29–30 feet) long and around 250–270 kg (about 550 pounds) in weight.

Quick size snapshot

  • Maximum reported size (green anaconda): Up to about 8–9 meters (26–30 feet) in length in strong modern sources.
  • Typical large adult: More commonly around 4–5 meters (13–16 feet), especially for males, with big females often larger.
  • Weight: The heaviest confirmed individuals reach about 250 kg (≈550 lb), making the green anaconda likely the heaviest snake species in the world.
  • Thickness: Body diameter can be around 30 cm (about 12 inches) across in very large individuals.

Species differences

  • Green anaconda (the giant one people usually mean):
    • Up to about 9 meters (29–30 feet) and ~250 kg in the biggest verified records.
* Common adults are smaller, but still huge compared with most snakes.
  • Yellow/southern anaconda:
    • Much smaller, usually up to about 4–4.6 meters (roughly 13–15 feet).

Myths vs reality

  • There are many stories claiming anacondas over 10–12 meters (35–40 feet), but these are not supported by reliable scientific measurements.
  • The longest rigorously measured green anacondas are under 9 meters, and many famous “monster” photos turn out to involve camera angles or unverified estimates.

TL;DR: When people ask “how big is an anaconda,” the realistic top end is around 8–9 meters long, 250–270 kg in weight, and roughly as thick as a large person’s torso.

Information gathered from public forums or data available on the internet and portrayed here.