How Big Do Millipedes Get? Species Size Comparison Guide

How big do millipedes get? The answer depends heavily on the species — and size is one of the most important factors when choosing the right millipede for your setup.

Some millipedes stay small and discreet, while others grow into massive, impressive display animals. Whether you want a giant showpiece or a smaller bioactive helper, understanding size differences will help you make the right choice.

If you're ready to browse available species, explore our live millipedes for sale and find the perfect fit for your enclosure.

Millipede Size Comparison (By Popular Species)

🟢 Small Millipedes ( 2.5 inches or Less)

Examples:

• Bumblebee Millipede (Anadenobolus monilicornis)
• Scarlett Millipede, Trigonilus coralinus
• Mozambique Fire Millipede, Centrobolus splendidus 
• Hawaiian Striped Millipede, Spirobolellus, sp. Maui

Traits:

• Compact and easy to house
• Require less space and substrate depth
• Often more active on the surface
• The above species do best at higher temperatures e.g. 80F to 85F - * This is not true for all small species

👉 Best for: Small enclosures who want low-maintenance pets

🟡 Medium Millipedes (3.5 – 5 inches)

Examples:

• Ivory Millipede (Chicobolus spinigerus)
  
• Florida Scrub Millipede, Floridobolus floydi
• Spotted White Tree Millipede, Anadenobolus gundlachi
• Bi Color Avatar Millipede, Salpidobolus sp. 
• Thai Rainbow Millipede, Atoppochetus caudulanus
• Banded Pink Foot Millipede, Narceus americanus
• Yellow Banded Oak Millipede, Narceus gordanus

Traits:

• Ideal balance of size and manageability
• Easy to care for and available at  The Defiant Forest website

🔴 Large Millipedes (5.5 – 10+ inches)

Examples:

• Giant African Millipede (Archispirostreptus gigas)
• Giant Olive Speckled Leg Millipede, Telodeinopus aoutii
• Goliath Yellow Leg Tree Millipede, Harpagophoridae, sp.
• Giant Texas Gold Millipede, Orthroporus ornatus
• Giant Chocolate Millipede, Orthroporus ornatus
• Giant Red Leg Tree Millipede, Balustreptus falcatus
• Giant Thai Orange Millipede, Thyropygus sp.

Traits:

• Impressive size and visual appeal
• Slower movement, very docile
• Require deeper substrate and more space

👉 Best for: Keepers looking for a true “display animal”

🧠 What Affects Millipede Size?

Not all individuals grow the same. Size depends on:

• Species genetics (biggest factor)
• Diet quality (leaf litter, decaying wood, calcium)
• Humidity and substrate depth
• Age and molting cycles

Millipedes grow slowly over time, molting in stages rather than reaching full size quickly.

📊 Average Millipede Size Chart

🏡 Choosing the Right Size for Your Setup

When deciding on a millipede, size impacts:

🪵 Enclosure Space

Larger species need:

• More floor space
• Deeper substrate for burrowing
• Good Quality Millipede Substrate

🌿 Substrate Depth

A good rule:
👉 At least 1 to 1.5× the length of the millipede

👀 Visibility

• Smaller species may stay hidden more often
• Larger species are easier to observe

❓ Do Millipedes Keep Growing?

Yes — millipedes grow through a process called molting.

Each molt adds:

• Body segments
• Length
• Mass

Growth slows as they mature, but many species continue gradual development throughout their lives.

🔗 Related Guides

• Best Pet Millipede Species (Ranked Guide)
• Millipede Substrate Depth & Moisture Guide
• What Do Millipedes Eat?
• How Long Do Millipedes Live?

🛒 Find the Right Size for You

Whether you want a small, easy-care species or a massive showpiece, choosing the right size is key to long-term success.

Browse our live millipedes for sale to find beginner-friendly options, large display species, and bioactive-ready detritivores — all carefully packed and shipped with temperature control.