People frequently ask, “How high up do I put the mezuzah on an archway?” It is a great question, and it is a little more complicated than a regular rectangular doorway.
On a standard doorframe, the halacha (הֲלָכָה, Jewish law) is usually much simpler: the mezuzah is placed at the bottom of the top third of the doorway. In practical terms, you measure the doorway height, divide it into three parts, and place the mezuzah just above the line where the top third begins. You can read our full guide on how high the mezuzah should be.
Why Mezuzah Placement on an Archway Is Different
A regular doorway has a clear top. An archway does not. That is where the question begins: what do we consider the “top” of an arched doorway for mezuzah placement?
The most obvious answer might be to measure from the highest point of the arch. The problem is that the very top of an arch is only a single point on a curve. It does not have real doorway width at that exact point.
According to halacha, a doorway must have certain minimum dimensions in order to require a mezuzah. The common discussion includes a minimum width of four tefachim (טְפָחִים, handbreadths) and a minimum height of ten tefachim. Ohr Somayach summarizes this requirement by noting that a doorway must have a minimum height of ten tefachim and, in practical halacha, a minimum width of four tefachim. You can see their discussion of doorway requirements and unusual mezuzah cases here: Rambam’s Top Ten.
That is why we do not simply measure an archway from the highest point. The highest point may be visually the top of the arch, but halachically it may not function as the top of a usable doorway space.
The Common Mezuzah Archway Calculation: Four Tefachim Wide
The most commonly accepted opinion is to measure from the first place in the arch where you can square out four tefachim. A tefach (טֶפַח, handbreadth) is a halachic unit of measurement. One commonly used estimate is about 3.16 inches, though exact measurements can vary by opinion and community practice.
According to this approach, the first point where the arch is wide enough to be considered a doorway becomes the halachic “top” of the opening. From there, you measure down to the floor, divide that height by three, and place the mezuzah at the bottom of the top third.
This approach keeps the mezuzah connected to the part of the opening that has enough width to be considered a doorway. For most people asking where to put a mezuzah on an arched doorway, this is the approach they are usually being shown.
Another Halachic Opinion: Measuring From Where the Arch Begins to Curve
There is another opinion that treats the curved portion of the arch differently. According to this approach, if the straight vertical sides of the doorway are at least ten tefachim high before the arch begins, the curve above that point is treated more like the mashkof (מַשְׁקוֹף, lintel) than the doorpost itself.
In that case, you measure from the floor only up to the place where the arch begins to curve. Then you divide that straight section into thirds and place the mezuzah at the bottom of the top third of the straight part.
This can produce a surprising result. In theory, if an archway had a straight section that was only about three feet high and then a much taller rounded section above it, this opinion could place the mezuzah much lower than people expect. That is one reason arched doorways should not be treated casually.
Mezuzah Maven explains this same basic issue: some authorities measure only the straight post before the arch begins, while other authorities look at the top third of the full opening and may allow placement in the curved area. You can review that discussion here: Archways: Placement on Curve or Post.
Should a Mezuzah Go on the Curve of an Archway?
This depends on the doorway and the halachic approach being followed. Some opinions avoid placing the mezuzah on the curved part of the arch when the straight vertical post is halachically usable. Other opinions may allow or require calculating from the broader archway opening, depending on the exact structure.
The important point is that an archway is not always measured like a standard rectangular doorway. The shape of the entrance, the width of the opening, the height of the straight side posts, and the local minhag (מִנְהָג, custom) can all matter.
What About the Right Side and the Mezuzah Blessing?
Even once you know the height, you still need to place the mezuzah on the correct side of the doorway. In many cases this is simple, but interior doorways and unusual openings can be more complicated. For more on that topic, see our guide to which side of the door the mezuzah goes on.
You should also know when to recite the bracha (בְּרָכָה, blessing). If the archway creates a doubtful obligation, or if you are not sure whether the doorway requires a mezuzah with a blessing, speak with a competent rabbi before making the blessing. You can review the standard wording in our guide to what blessing is said on the mezuzah.
Choosing a Mezuzah Case for an Archway
Once the placement is clear, make sure the mezuzah case physically works for that spot. Some archways have narrow trim, curved surfaces, stonework, or molding that can make mounting more difficult. A slim mezuzah case may be easier to position properly on a narrow or unusual doorpost.
If the archway is outdoors or exposed to moisture, choose a case that can better protect the scroll. You can browse outdoor mezuzahs for entrances that need more durable protection. For interior archways, you may have more flexibility with decorative mezuzah cases, as long as the kosher scroll fits safely inside.
The most important part is still the klaf (קְלָף, parchment) inside. A beautiful case enhances the mitzvah through hiddur mitzvah (הִדּוּר מִצְוָה, beautifying a commandment), but the mitzvah depends on a kosher scroll written by a qualified sofer STaM (סוֹפֵר סת״ם, Jewish scribe). You can learn more in our article on what makes a kosher mezuzah, or browse our kosher mezuzah scrolls.
Final Thought on Mezuzah Placement for Arched Doorways
For a regular rectangular doorway, mezuzah placement is usually straightforward. For an archway, the calculation can depend on where the doorway becomes halachically wide enough, whether the straight side posts are ten tefachim high, and which opinion or community custom you follow.
Because arched doorways can vary so much, this article should be treated as general educational guidance, not a personal halachic ruling. If you have an arched doorway in your home and are unsure where to place the mezuzah, the best next step is to ask a competent rabbi who can look at the actual doorway or review clear photos and measurements.
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