---
title: Comparing Frame Sizes Dimension by Dimension
description: How to compare lens, bridge, temple and frame width in mm, why frame width is not 2 × lens + bridge, and what the numbers leave out.
updated: 2026-09-25
---
# Comparing Frame Sizes Dimension by Dimension

To compare two frames, check each dimension on its own. A single "size" number can hide real differences.

## Compare each number separately

Two frames can match on one number and differ on another. Maui Jim lists the standard Ho'okipa at 64-14-140 ([Maui Jim](https://www.mauijim.com/US/en_US/shop/sunglasses/rimless/ho-okipa?variantCode=407-02)). It lists the Ho'okipa Universal Fit at 64-14-145 ([Maui Jim](https://www.mauijim.com/US/en_US/shop/sunglasses/rimless/ho-okipa-universal-fit?variantCode=407N-02)). Lens and bridge are the same, but the temples differ by 5 mm.

When comparing, report the difference in mm for each field. If either value is null, report the difference as unknown, not as zero.

## Small differences and rounding

Makers state these sizes; this site has not measured them. Pages round in different ways: some give whole numbers and some give decimals such as 56.3 mm. Sources can also disagree. The catalog notes that one retailer publishes its own self-measured Holbrook figures, which differ from Oakley's, and those figures were not recorded ([Oakley Standard Issue](https://www.oakleysi.com/en-us/product/W0OO9102?variant=888392335920)). Treat a difference of a millimeter or less as uncertain. It is not a meaningful difference.

## Why frame width is not 2 × lens + bridge

Frame width is the overall width of the front, and this catalog stores it only when the maker states it. The front includes the rim and the end pieces, and a curved (wrapped) front is wider when laid flat than when viewed head-on. The formula therefore doesn't hold:

| Model | Lens | Bridge | 2 × lens + bridge | Stated frame width |
|---|---|---|---|---|
| Oakley Holbrook OO9102 | 57 | 18 | 132 | 140 |
| Oakley Frogskins Lite OO9374 | 63.2 | 10 | 136.4 | 131.79 |

Sources: [Holbrook](https://www.oakleysi.com/en-us/product/W0OO9102?variant=888392335920), [Frogskins Lite](https://www.oakleysi.com/en-us/product/W0OO9374?variant=888392326843).

## What the numbers don't capture

- **Wrap and curvature.** Two fronts with the same width can sit very differently.
- **Hinges and temple shape.** Spring hinges and how far the arms flare aren't recorded.
- **Nose pads.** `adjustable_nosepads` is true only when the maker says so. The Maui Jim Ka'ouo Asian Fit page states built-up nose pads, which are fixed rather than adjustable, so the field is left empty ([Maui Jim](https://www.mauijim.com/US/en_US/shop/sunglasses/classic/ka%E2%80%98ouo-asian-fit?variantCode=GS625-02)).

Matching numbers do not guarantee the same fit.

## Related

- [/guides/how-to-read-temple-size-markings](/guides/how-to-read-temple-size-markings)
- [/guides/bridge-fit-labels](/guides/bridge-fit-labels)
- [/docs/compare_sunglasses.md](/docs/compare_sunglasses.md)
- [/docs/data-dictionary.md](/docs/data-dictionary.md)
- [/docs/sources-and-methodology.md](/docs/sources-and-methodology.md)