Quick answer: measure a hoop straight across its widest point. The outer diameter runs from outside edge to outside edge; the inner diameter runs across the open space inside the hoop. Inner diameter is often the more useful number when checking whether a hoop will clear your earlobe.
Inner diameter vs. outer diameter
| Measurement | Where to measure | Why it matters |
|---|---|---|
| Outer diameter | Outside edge to outside edge | Shows the overall visual size |
| Inner diameter | Inside edge to inside edge | Shows the usable opening around the lobe |
| Wire thickness | Across the hoop's tube or wire | Changes the opening and visual weight |
| Total drop | Top of the post to the lowest point | Useful for oval or irregular hoops |
Measure a hoop at home
- Close the hoop gently so it is in its normal wearing shape.
- Place it on a flat surface and use a millimeter ruler or caliper.
- Measure the widest outside span without following the curve.
- Measure the opening between the inside edges.
- Record thickness separately; do not subtract an estimated thickness if you can measure the opening directly.
For a simple circular hoop, inner diameter is approximately outer diameter minus twice the wire thickness. For example, a 20 mm outer diameter hoop with 2 mm thick wire has an opening of roughly 16 mm. Hinges, flattened profiles and oval shapes can make this shortcut inaccurate, so a direct inner measurement is better.
What to check on an online product page
Look for a dimension diagram and confirm the unit. Some sellers list height, some list diameter, and some use a total drop measurement. If a product page gives only one number, ask what points were measured. Also check whether the post or hinge reduces the available opening.
StaryMagic's Handmade Minimalist Hoop Earrings list a 60 mm size. Review the product details before ordering if you need a particular opening or profile. You can compare other silhouettes in the Geometric Earrings collection.
Related guides
See the hoop earring size chart, fit guide, and huggie vs. hoop comparison.
Frequently asked questions
Which measurement tells me if a hoop will fit my lobe?
Inner diameter is the most useful starting point, but piercing position and lobe thickness also matter.
Is hoop size measured in millimeters?
Many jewelry listings use millimeters, but some use inches. Check the unit and the measurement points.
Does thickness change the fit?
Yes. A thicker hoop has a smaller opening than a thinner hoop with the same outer diameter.
Can I measure an oval hoop the same way?
Measure both its height and width, then check the inner opening at the narrowest point.
Shop with confidence: compare the measurements on StaryMagic's hoop earrings and browse the earring collection for other shapes.