The sewing machine throat space chart

Throat space is the opening between the needle and the body of a sewing machine: the tunnel a rolled quilt passes through. Harp space is the same measurement under a different name. It has two dimensions, width and height, and manufacturers publish them in at least three different ways - width only, width then height, or height then width - frequently without saying which is which.

The chart

Every figure below was read from the linked manufacturer page on 1 September 2026 and normalized to width x height in inches. The last column shows the maker’s original wording, so you can check that we have not quietly reversed anything.

How we normalized this

Three rules, applied to every row:

1. Everything converts to inches, with millimeters retained where the maker published them. Juki and Janome publish in millimeters; Brother and bernette publish in inches. 25.4 mm to the inch, rounded to two decimal places.
2. Width first, always. Where a maker published height first we reordered it and said so in the last column. We resolved the ambiguous cases against physical geometry: 8.7 inches is a plausible needle-to-arm width and an implausible arm height, and the machine is listed by dealers as a 9-inch arm.
3. Unpublished figures stay unpublished. Four machines here have no published height. Those rows say “not published” and their opening says “cannot be calculated”. We did not estimate them, and any chart that gives you a number for those rows produced it from somewhere other than the manufacturer.

Why manufacturers publish this three different ways

There is no standard, and the term itself is doubled. “Throat space” and “harp space” are the same measurement - we cover the terminology here - and beyond that there is no convention about which dimension leads.

The clearest illustration is Brother against itself. On the SE700 it publishes “6.4″ x 4.0″ work area” and on the NQ3550W “8.3″ x 4.1″ of usable space” - both width first. On the PQ1600S it publishes “5.7″ x 8.7″ needle-to-arm space” - height first. Same manufacturer, same website, no label on either.

Juki is the outlier that shows how easy this would be to fix: “215(W) x 150(H)mm / 8.5″(W) x 6″(H)”. Both unit systems, both dimensions, each labeled.

Why height binds before width

What passes through the throat when you quilt is half the quilt, rolled. A rolled quilt sandwich is roughly cylindrical, and a cylinder passing through a rectangular opening is limited by the smaller dimension.

You can always slide a roll further to the right if it is a bit long. You cannot compress it vertically past the point where the batting stops compressing. That is why 6 inches of height beats 10 inches of width in practice, and it is the single most useful thing in this chart.

Verified 1 September 2026

Every row on this chart was read on that date. We re-check the reference tables monthly against the manufacturer pages, and where a figure changes we update it and change the date. If you find a row that no longer matches its source page, tell us - that is the one message we always act on.