If you are choosing between a 210mm and a 240mm gyuto, you will find plenty of advice in English, much of it from people who already own several knives. I went to the Japanese pages of two knife shops in Sakai instead, because they sell both sizes and have no reason to push one. They agree with each other, and the line they draw is between a home kitchen and a professional one.
What the two shops say
Jikko, a knife shop in Sakai, publishes a size guide for every kind of knife it sells, with one standard size for cooks and one for homes. For the gyuto it gives 240mm for professional cooks and 210mm for home use. It also says that because the gyuto is an all-purpose knife, a slightly longer blade is easier for jobs like peeling and shaping vegetables, so it does not tell anyone to go short.
Sakai Ichimonji Mitsuhide, another Sakai shop, splits the gyuto into three ranges by how the knife will be used.
180 to 210mm is for people who want an all-purpose knife, or who want a knife for the home and prefer a slim blade. It says this size is popular in homes as a replacement for the santoku.
210 to 240mm is for people who want one knife for general restaurant cooking, used on everything from a block of meat to a tomato. The shop says this is the most widely sold size among professional knives.
270 to 330mm is for people who prep large amounts of vegetables or fish, like shredding a lot of cabbage or breaking down tuna at a market.
Its summary at the end recommends 180mm for the home as well, and 210 to 240mm as the all-purpose knife in a restaurant.
So 210mm is the size both shops treat as the home gyuto, and 240mm is the size they treat as the working knife in a professional kitchen.
Why the home size is shorter
Neither shop is saying that a 240mm knife cuts worse. The difference is the space around it. A restaurant cook works on a large board on a long counter. A home cook usually does not.
I quoted Tojiro on this in my comparison of gyuto, santoku and bunka. In an interview a Tojiro representative said that if a knife is too long it becomes hard to work on the cutting board, so you should choose after looking at the size of your kitchen and your board. The same interview gives 21cm as the gyuto size for a normal home.
The extra 30mm of blade is not the only thing that grows. In the Sakai Takayuki Grand Chef series, which I priced below, the 210mm gyuto is 325mm long overall and the 240mm is 370mm. That is 45mm more knife on the board and about 40g more in the hand.
A detail about how length is measured
Jikko points out that for a gyuto with a Western handle, the size is the length of the edge. For knives with a Japanese-style handle, some makers measure from the tip to the end of the blade where it meets the handle instead.
In practice this means two knives both sold as 240mm can have edges of slightly different lengths. If the exact length matters to you, compare the edge length in the listing, and if only the size is given, ask the shop.
The same knife in both lengths
To see what the extra 30mm costs on its own, I compared four series on Hocho-Knife, a Japanese knife retailer, on 1 October 2026. All eight knives were in stock.
The Sakai Takayuki Grand Chef, a stainless knife from a Bohler-Uddeholm steel listed at about HRC 61 to 62, is $151.99 at 210mm and $176.99 at 240mm. Both were on sale on that date, marked down from $181.99 and $212.99. The 210mm weighs 180g and the 240mm 220g.
The Sakai Takayuki Aoniko, a Blue 2 carbon steel knife, is $199.99 at 210mm and $204.99 at 240mm. The weights listed are 153g and 221g.
The Sakai Takayuki 63-layer Damascus is $263.99 at 210mm and $347.99 at 240mm, with weights of 186g and 242g.
The Fujiwara Kanefusa gyuto is $80.99 at 210mm, also on sale that day, and $97.99 at 240mm.
The gap runs from 5 dollars to 84 dollars. In the cheaper series it is small enough to ignore. In the Damascus series it is a third of the price again. In every series where the weight is listed, the 240mm is noticeably heavier, by 40 to 68g.
Which one to buy
Measure your cutting board first. A 240mm gyuto is about 37cm long from tip to handle end, and you need room to draw the full edge across the board without the handle hitting the counter edge or the wall.
Buy a 210mm gyuto if you cook at home, your board is an ordinary household size, and this is going to be your main knife. It is the size both Sakai shops recommend for a home, it is lighter, and it is cheaper in every series I checked.
Buy a 240mm gyuto if you have a large board and counter, you often cut big things like a whole cabbage, a squash or a large roast, or you cook professionally or want to practise the way a restaurant cook works. Ichimonji calls this the most common professional size for a reason.
If your kitchen is small, or you mostly cut for one or two people, look at 180mm, which Ichimonji also recommends for homes, or at a santoku. The choice between those shapes is in gyuto vs santoku vs bunka, and the sequence I would buy knives in is in how to choose a Japanese knife.
The two knives
For most home cooks: the Sakai Takayuki Grand Chef gyuto 210mm at $151.99. Stainless, double-edged, 180g, in stock and on sale on 1 October 2026.
For a large board or a professional kitchen: the Sakai Takayuki Grand Chef gyuto 240mm at $176.99. Same steel, 220g, also in stock and on sale on the same date.
Sale prices end without notice, so check the price on the page before you buy.
Disclosure
I have four approved affiliate partnerships: two with knife retailers, Hocho-Knife and SharpEdge, and two with Japanese language-learning companies unrelated to knives. This page carries two tracked links, both to Hocho-Knife. At about 10 percent, that is roughly 15 dollars for the 210mm and 18 dollars for the 240mm. The knife I recommend to most readers is the 210mm, which pays me less. My full affiliate disclosure is here.
Sources, checked on 1 October 2026: the Jikko Japanese size guide, the Sakai Ichimonji Mitsuhide Japanese page on the gyuto, the Tojiro interview cited in my gyuto, santoku and bunka article, and the Hocho-Knife product pages for the Sakai Takayuki and Fujiwara Kanefusa knives above.