How to Measure Hoop Earrings: A Complete Size Guide

on Aug 13 2026
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    Learning how to measure hoop earrings is actually easy. You just need to know where to measure, what the number means, and how it relates to your ear. Once you understand that, choosing between 10 mm, 20 mm, 30 mm, or 50 mm hoops becomes much easier. 

    Key Takeaways

    • Hoop earrings are commonly measured in millimeters (mm).

    • Inner diameter measures the open space inside the hoop.

    • Outer diameter measures the hoop from outside edge to outside edge.

    • A hoop's thickness affects its inner and outer diameter, so two hoops with the same outer diameter may have different openings.

    • To measure your ear for a hoop, measure from the piercing hole to the edge of your earlobe.

    • Don't assume a listed size such as 20 mm refers to the inner opening. Check the seller's measurement specifications.

    • Gauge and hoop diameter are different measurements. Gauge describes jewelry thickness, not the overall size of the hoop.

    How Are Hoop Earrings Measured?

    Diagram showing how to measure a hoop earring, including inner diameter, outer diameter, thickness, and center point

    Hoop earrings are measured in millimeters (mm). The measurement tells you how wide the hoop is from one side to the other. But there is one thing to watch for: some sellers measure the inside of the hoop, while others measure the outside.

    • Inner Diameter: The inner diameter is the open space inside the hoop. It tells you how much room the hoop has for your ear.

    • Outer Diameter: The outer diameter measures the hoop from its outside edge to the other outside edge. It tells you how big the whole hoop is.

    The inner diameter tells you about the space inside the hoop. The outer diameter tells you about its overall size.

    Why Does This Matter?

    Let's say two hoops are listed as 20 mm. If one is thin and the other is thick, they won't have the same amount of space inside. The thicker hoop will have a smaller opening. So, don't just look at “20 mm” when buying hoops. Check whether the seller means inner diameter or outer diameter.

    How to Measure Hoop Earrings You Already Own

    If you already have a pair of hoops and want to know their size, you can measure them with a ruler. A measuring caliper can give you a more precise result, but it isn't necessary for a basic measurement.

    How to Measure the Inner Diameter

    1. Lay the hoop flat.

    2. Find the widest part of the hoop.

    3. Place your ruler across the center.

    4. Measure from the inside edge to the opposite inside edge.

    5. Write down the measurement in millimeters.

    That number is the hoop's inner diameter.

    How to Measure the Outer Diameter

    Follow the same steps, but measure from the outside edge to the opposite outside edge. That number is the hoop's outer diameter.

    Don't Measure the Clasp

    If your hoop has a hinge, clasp, or other closure, don't include it in the measurement. Measure the circular part of the hoop itself. For example, if the outside of the hoop measures 20 mm, you have a 20 mm outer diameter hoop. But its inner opening will be smaller because the metal takes up some of that space.

    How to Measure Your Ear for Hoop Earrings

    Measuring an existing hoop tells you its size. Measuring your ear helps you figure out what size hoop you may need. The easiest way is to measure the distance from your piercing hole to the edge of your earlobe.

    • Step 1: Find Your Piercing: Look at the hole where you normally wear your hoop.

    • Step 2: Measure to the Edge of Your Earlobe: Using a ruler, measure the straight-line distance from the center of the piercing hole to the edge of your earlobe.

    • Step 3: Double the Measurement: Because a diameter goes all the way across a circle, double that number.

    So, an inner diameter of about 16 mm would reach roughly from the piercing to the edge of the lobe. But this is only a starting point. You may want a smaller hoop for a snug look or a larger one if you want more space and movement.

    Why Your Piercing Position Matters

    Two people can have similar-sized ears but need different hoop sizes. Their piercing holes may sit at different distances from the edge of the earlobe. Your piercing position, lobe shape, hoop thickness, and the way you want the hoop to sit can all affect the size you choose.

    Hoop Earring Size Chart

    Hoop sizes can be hard to understand from a number alone. A 10 mm hoop and a 30 mm hoop may not sound different, but the difference is easy to see when you compare them side by side. The chart below gives you a quick idea of how common hoop sizes compare.

    Hoop size

    Inches

    General size

    5 mm

    0.20 in

    Very small

    8 mm

    0.31 in

    Small

    10 mm

    0.39 in

    Small

    12 mm

    0.47 in

    Small

    15 mm

    0.59 in

    Small to medium

    20 mm

    0.79 in

    Medium

    25 mm

    0.98 in

    Medium to large

    30 mm

    1.18 in

    Large

    40 mm

    1.57 in

    Large

    50 mm

    1.97 in

    Very large

    Important: These size descriptions are only general visual guides. There is no single industry rule that says a particular number of millimeters must be called “small,” “medium,” or “large.”

    Hoop Earring Size on the Ear

    Hoop earring size chart showing 10mm, 20mm, 30mm, 40mm, and 50mm hoop sizes on the ear

    What is earring gauge?

    As we discussed, diameter measures how big a space an earring has inside and how it is actually sized, as inner and outer diameter, but gauge is the thickness of the part that pierces through your piercing. 

    Earring Gauge Size Chart

    Gauge

    Millimeters

    Common use

    22g

    0.6 mm

    Thin, delicate posts

    20g

    0.8 mm

    Standard lobe piercings, butterfly-back studs

    18g

    1.0 mm

    Standard lobe piercings, professional piercing needles

    16g

    1.2 mm

    Cartilage, helix, tragus, conch

    14g

    1.4 mm

    Some cartilage and body piercings

    12g

    1.6 mm

    Stretched piercings

    Note:

    Remember, gauge works backward. The smaller the number, the thicker the post. A 16g earring is thicker than an 18g earring, even though 16 is a smaller number than 18. Most people with standard lobe piercings wear 20g or 18g without ever checking the label, since that's what butterfly-back studs and small hoops are typically made in.

    Read About: Types Of Ear Piercings

    How to Choose the Right Hoop Earring Size

    For a snug everyday look

    Smaller hoops sit close to the earlobe and barely move when you turn your head. This kind of fit works well for anyone who wears earrings all day, every day. A snug hoop also tends to catch less on hair, scarves, or phone calls.

    For a classic medium hoop

    Medium hoops strike a balance between visibility and ease. They're noticeable without dominating the face, and they tend to suit the widest range of face shapes and outfits. This size range is often the safest starting point if you're unsure what to buy.

    For a statement hoop

    Larger hoops are meant to be seen. They add movement, catch light differently than smaller styles, and naturally draw the eye toward the face. Statement hoops work well for occasions where you want the earrings to be part of the outfit's story, not just a quiet detail.

    For small or high lobe piercings

    If your piercing sits higher on the lobe or the lobe itself is on the smaller side, inner diameter becomes the number that matters most. A hoop with too much open space can feel loose or hang at an awkward angle. Checking inner diameter first, before outer diameter or overall style, helps avoid a hoop that never quite sits right.

    For multiple ear piercings

    Stacking hoops across multiple piercings adds a layer of planning that single-piercing shopping doesn't require. Smaller hoops generally sit closer to the ear and work well in tighter piercing clusters, while a single larger hoop can anchor the look from a lower or more prominent piercing. Spacing between piercings will often decide how many hoops can comfortably sit next to each other without overlapping.

     

    Frequently Asked Questions

    Hoop earrings are generally measured by their inside diameter, meaning the distance straight across the open space from one inner edge to the other. This measurement is more useful for fit because it tells you how much room the hoop has around your earlobe.

    A 20 mm hoop refers to a hoop with an approximately 20-millimeter diameter, usually measured across the inside of the hoop. That is about 0.79 inches. A 20 mm hoop is generally considered a small-to-medium size and can create a subtle everyday look, depending on your piercing placement and ear size.

    Measure the distance from the center of your piercing to the edge of your earlobe. Your hoop's inner diameter needs to provide enough space to fit around that distance, with additional room depending on how snug or loose you want the hoop to sit. Piercing placement and ear anatomy vary, so there is no universal hoop size that fits everyone.

    No. Hoop size and gauge describe two different measurements. Hoop size refers to the diameter of the hoop, while gauge refers to the thickness of the metal or wire. For example, a hoop could have a 20 mm inner diameter and come in different thicknesses or gauges.

    There is no single universal smallest hoop size. Very small huggie and hoop styles can measure around 6–10 mm in diameter, while the size that can actually fit depends on your piercing placement and ear anatomy. Smaller hoops may work well for closely fitted styles, but not every ear can comfortably accommodate the same diameter.

    There is no single “normal” earring size because earrings come in different styles. Studs, huggies, hoops, and statement earrings all use different dimensions. For hoops, smaller huggies may be around 8–12 mm, medium styles often fall around 20–40 mm, and larger statement hoops can go beyond 40 mm.

    For many people, 20–40 mm hoops offer a versatile everyday range. Smaller 10–20 mm hoops create a subtle look, while 30–40 mm hoops provide more visible presence without the dramatic look of oversized hoops. The best everyday size depends on your ear anatomy, piercing position, comfort, and personal style.

    If you don't have a ruler, use a piece of string and a known-size reference. Place the string straight across the hoop's inner diameter and mark where it meets the two inner edges. You can then compare that length with a ruler or another accurately measured object when one becomes available.

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