Which Post Length Should You Choose? 5mm, 6mm, or 8mm Flatback Earrings
If you’ve ever worn a stud that felt too tight (pinching your earlobe) or too long (snagging on your mask or pillow), you already know: post length matters.
At our shop, most of our internally threaded flatback earrings come in three post lengths – 5mm, 6mm, and 8mm. But how do you know which one is right for your piercing?
This guide will help you choose based on your piercing location, healing stage, and personal comfort.
Why Post Length Is Important
The post is the straight rod that goes through your piercing. If it’s too short, swelling has nowhere to go, and the earring can embed into your skin. If it’s too long, the extra space lets the earring move around, irritating the piercing and catching on hair, clothes, or pillows.
The perfect post length should:
-Allow 0.5–1mm of slight movement when your piercing is fully healed.
-Leave no deep indentation on your skin.
-Not stick out so far that the back disc floats away from your ear.
The Three Lengths We Offer
| Post Length | Best For | Why |
|---|---|---|
| 5mm | Tragus, snug, daith, conch (small, tight cartilage piercings) | These piercings have thin tissue. A shorter post stays flush and doesn’t protrude inside the ear canal or bump against opposite ridges. |
| 6mm | Standard lobe piercings (healed), helix, forward helix, most cartilage (average thickness) | The “just right” length for most healed piercings – comfortable, secure, and rarely too tight or too loose. |
| 8mm | Healing piercings (initial jewelry), thick earlobes, swollen cartilage, some nipple piercings (with flatback adapters) | Extra room for swelling during healing. Also suitable for naturally thick anatomy (e.g., chunky lobes or industrial piercings). |
Detailed Guide: How to Choose Your Length
✅ Choose 5mm If…
-You have a tragus piercing – The tragus is a thin flap of cartilage. An 8mm post would stick out and poke the inside of your ear canal. 5mm sits perfectly.
-You have a snug or daith – These piercings are located in tight folds. Longer posts cause constant friction.
-Your cartilage piercing is over 1 year old and fully healed, and you prefer a snug, minimalist fit.
-You want to stack multiple lobe piercings without posts bumping into each other behind the ear.
⚠️ Do not use 5mm on a healing or swollen piercing. It will be too tight and painful.
✅ Choose 6mm If…
-You have standard earlobe piercings (first, second, or third holes) that are fully healed (at least 6 months old).
-Your helix or forward helix is healed, and you want a secure fit without extra length.
-You’re between sizes – 5mm feels slightly tight, but 8mm moves too much. 6mm is the perfect middle ground.
-You don’t want the flatback disc to leave a mark, but you still want the earring to feel secure.
💡 For most people, 6mm is the default choice for healed lobe and cartilage piercings.
✅ Choose 8mm If…
-Your piercing is healing – Whether it’s a fresh lobe (first 2–3 months) or a new cartilage piercing (first 6–9 months), you need room for swelling. 8mm gives that room.
-You have thick or fleshy earlobes – Some people simply have more tissue. A 6mm post may not even reach the back of the lobe. Go with 8mm.
-You experience frequent swelling (e.g., due to allergies, sleeping on that side, or hormonal cycles).
-You’re wearing the earring in a nipple piercing (using a flatback adapter) – Nipple tissue requires longer posts, typically 8mm–10mm.
-You want to be able to clean the piercing easily – The extra length makes it easier to get saline spray behind the earring.
⚠️ Once swelling goes down (usually after 4–8 weeks for lobes, 3–6 months for cartilage), you should downsize to 6mm or 5mm to prevent snagging and irritation.
How to Measure Your Own Piercing Thickness (Without a Ruler)
If you’re still unsure, here’s a simple test:
1. Take a standard 6mm post (or a clean toothpick marked at 6mm).
2. Insert it gently through your piercing until the flatback disc touches the back of your ear.
3. Look at the front – how much of the post is sticking out?
-Less than 1mm → You need 8mm (it’s too tight).
-1–2mm → 6mm is perfect.
-More than 2mm → You might prefer 5mm for a snug fit.
Or, just ask your piercer! They know your anatomy best.
Common Scenarios (Real Examples)
| Your Piercing | Healing Stage | Recommended Length |
|---|---|---|
| Fresh lobe piercing (2 weeks old) | Swelling active | 8mm |
| Lobe piercing (healed, 1 year old) | Fully healed | 6mm (or 5mm if thin lobe) |
| Tragus piercing (healed, 8 months) | Fully healed | 5mm |
| Helix piercing (just pierced) | Fresh / swollen | 8mm |
| Helix piercing (healed, 2 years old) | No swelling | 6mm (or 5mm if thin ear) |
| Thick earlobe (healed) | Healed, but tissue is thick | 8mm |
| Conch piercing (healed) | Fully healed | 5mm or 6mm (depends on ear anatomy) |
Still Not Sure? Start With 6mm (And Add an 8mm for Healing)
If you’re buying for a healed piercing and have average anatomy, 6mm works for 80% of people. But if you’re buying for a fresh piercing or you have thicker ears, choose 8mm first. You can always downsize later.
Final Tip: When in Doubt, Go Longer (But Downsize Later)
It’s safer to start with an 8mm post during healing and then switch to a shorter post once swelling is gone. Wearing a post that’s too short can lead to embedding, infection, and pain. Wearing a post that’s too long is mostly just annoying – and you can fix it by swapping posts.
— Written by The A Pierce of Life Team
Have a specific piercing we didn’t mention? Leave a comment and we’ll help you choose the right length.