3149: Measure Twice, Cut Once

Measure Twice, Cut Once

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Title text: "Measure zero times, cut zero times." --carpenter who has achieved enlightenment and realized the wood is fine where it is

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Explanation

This strip centers around the saying "Measure twice, cut once", which it identifies as a "carpentry proverb". The actual origins of the saying are not clear (it applies to many other trades and activities just as well as carpentry), but the meaning remains the same — it refers to the importance of planning and checking multiple times before acting, in order to prevent mistakes (in all avenues of life — not just where cutting is involved). When a job requires cutting material to particular specifications, cuts are generally not practical to undo. If a cut is made in error, there are several possibilities, none of which are desirable. In some cases, the piece can be saved with additional work, which takes additional time and effort. If the error is minor, the piece might be used anyway, but that will result in ill-fitting pieces and an inferior end product. If none of that works, then the material has to be replaced by another piece, which must then be cut properly before the job can continue, wasting time, effort, and material. Experienced craftspeople quickly learn that the (usually fairly trivial) effort of double-checking measurements involves far less work and expense than dealing with the consequences of bad cuts.

The comic takes the proverb literally, showing a graph of various activities involving measuring and/or cutting, which shows the approximate ratio of measurements to cuts (though it does not provide actual values). From most to least measurements (top to bottom in the plot):

Surveyor (≥4 measurements, ~0 cuts)

Surveyors have the task of measuring land. They measure boundaries, elevations, and distances, but are rarely asked to physically cut anything themselves; they only produce measurements and maps, for which they typically would make multiple measurements to ensure accurate and thorough charts for those who will make later use of them.

Surveyors often need to have trees and bushes cleared from a property line to be able to see or measure from one corner to another. These are called "cuts" in some American jargon. However, surveyors may ask others to do this work, in advance, rather than do this themselves, and even then it would be "cut, then measure" rather than "measure, then cut".

Surgeon (~3 measurements, ~1 cut)

Surgery is a task requiring a great deal of precision, being on a living creature, not an inanimate object, and therefore having potentially more significant consequences if an error occurs. Surgery always involves cutting to some degree, but this is generally preceded by careful diagnosis, measurement and planning. It is important for surgeons to minimize the number of cuts that are made, and to keep those deliberate and precise to achieve their goals with as little trauma and damage as possible.

Good Carpenter (~2 measurements, ~1 cut)

The titular proverb at the core of the comic, that suggests that a good carpenter should follow a ratio of two measurements for every cut.

Careless Carpenter (~1 measurement, ~1 cut)

A careless carpenter would only make one measurement for every cut, resulting in an effectively equal ratio between the two. This is assumed to increase the incidence of bad cuts.

Really Bad Carpenter (<1 measurement, ~2 cuts)

A "really bad carpenter" is shown as making more cuts than measurements. This could be explained by the carpenter in question making cuts based on rough estimations rather than measurements, or by having to repeatedly recut many of their pieces, without measuring each time. This makes precision more or less impossible to achieve, and likely makes far inferior products, with much more waste (assuming the projects are even completed).

Serial Killer (0 measurements, ≥3 cuts)

This graph suggests a serial killer who kills with knives or other bladed instruments. Murder rarely involves actual measurements, because a low level of precision is often adequate to kill someone, and victims would not generally allow themselves to be measured.^{[citation needed]} Instead, killers would be expected to stab or slash at their victims repeatedly, resulting in a high number of cuts and no measurements at all. Alternatively, this may be a reference to the definition of serial killers as an individual who has killed three or more people in separate events.

Title text

The title text mentions a carpenter who has "achieved enlightenment", and does zero measuring and zero cutting, because they have "realized the wood is fine where it is". This is a play on the notion of philosophical enlightenment, where the epitome of expertise is pursued, not by better craftsmanship, but by coming to appreciate things as they already exist. Thus an "enlightened" carpenter would be pretty useless as a carpenter, as they would have no motivation to actually do carpentry.

Transcript

Caption at the top of the panel: "'Measure twice, cut once' -carpentry proverb" with boxes around "twice" and "once".

Below that, a scatter plot with X and Y axes labeled "number of cuts" and "number of measurements", respectively. At different places on the scatter plot lie six labels:

Surveyor: very high number of measurements, no cuts

Surgeon: high number of measurements, low number of cuts

Good carpenter: middling number of measurements, same number of cuts as surgeon

Careless carpenter: fewer measurements than good carpenter, same number of cuts as surgeon

Really bad carpenter: slightly fewer measurements than other carpenters, fairly high number of cuts

Serial killer: no measurements, very high number of cuts

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Discussion

Measure once, shame on you. Cut twice, shame on me! StapleFreeBatteries (talk) 00:57, 2 October 2025 (UTC)

You know, that's not a bad proverb! RadiantRainwing (talk) 00:58, 2 October 2025 (UTC)

I will cut you! Shame on me. 82.13.184.33 08:49, 2 October 2025 (UTC)

This is my first XKCD explained! 108.254.160.57 00:59, 2 October 2025 (UTC)

Hip hip hooray for you! You did a great job. RadiantRainwing (talk) 01:02, 2 October 2025 (UTC)

OK - but how many times did you check it before saving? 82.13.184.33 08:49, 2 October 2025 (UTC)

A fundamental problem with this comic is that a "good carpenter" really means "an efficient carpenter" (true of any craftsman, really). Economy of motion, skilled enough to know when to be really precise and to know when precision doesn't matter and is a waste of time. The efficient carpenter doesn't need to measure twice, he or she gets it right on the first try. Or, consistent with the above, knows their capabilities well enough so they can only measure twice when it's truly necessary. And, of course, some of the best efficiencies come from not "measuring" at all — using an end stop or a jig so the cut is easy and repeatable without measurement. Drawing a line (or cutting without a line) against the actual reference point rather than against an intermediate measurement tool (some might call this "scribing," but that suggests a level of precision that isn't what I mean). Effectively, "measure zero times, cut once." And in the opposite, sometimes the most efficient approach is not to measure at all (whether numerically or against a reference object), but to make a rough cut and then a finish cut — effectively, "measure zero times, cut twice." Also possible is if you are gang cutting a stack of N boards, you measure 0 times or once and then make 1 cut, so on a per-board basis it's measure once, cut 1/N. I don't know that all of these things are obvious, per se, but I can't help feel surprised that they don't seem to have been considered. JohnHawkinson (talk) 06:38, 2 October 2025 (UTC)

That seems to be more of an issue with the proverb, rather than the comic. 82.13.184.33 08:49, 2 October 2025 (UTC)

Are you saying my wall with studs just butt ended atop one another isn't good enough? Oh, fine then, I'll go add some bracing and maybe nails. SDSpivey (talk) 11:07, 2 October 2025 (UTC)

PLEASE STOP, YOU'RE KILLING ME!!!! --DollarStoreBa'al^converse 13:08, 2 October 2025 (UTC)

I do not concur. (At least not fully...) When cutting timber, there are usually two dimensions to measure, and to make the perfect cut you must somehow have measured those to dimensions. A surgeon, on the other hand, must also use the third dimension, knowing how deep into the body they cut.

Then, obviously, there are situations that differ. Say you want to half something, cutting along the diagonal. Or if you amputate a leg. But usually! :) Fomalhaut (talk) 11:37, 3 October 2025 (UTC)

Somewhat disappointed there's no joke about quantum mechanics, even in the title text. I guess figuring out how to fit the uncertainty principle here is left as exercise to the reader? 164.90.218.225 10:44, 2 October 2025 (UTC)

The title text seems to reference the Taoist concept of the uncarved block - https://en.wikipedia.org/wiki/Pu_(Taoism) 70.124.160.162 (talk) 13:18, 2 October 2025 (please sign your comments with ~~~~)

Possible reference to the real-life use of the reverse proverb (measure once cut twice) which is used by many makers. I am familiar with the concept from Adam Savage, but I don’t know if he’s the originator. The idea is that measurement is actually too imprecise of a tool and should only be used as an approximation. The final size of a piece will be based on something like a pressure fit. 98.36.13.95 (talk) 14:24, 2 October 2025 (please sign your comments with ~~~~)

About the title text, would the carpenter have to look or otherwise measure the wood to assume it's fine? Measure once, cut 0 times. -- L0L0Z1993 (talk) 15:19, 2 October 2025 (please sign your comments with ~~~~)

two measures one cut 2A0E:1D47:9098:3800:1126:180F:44A0:E826 18:07, 2 October 2025 (UTC)

Isn't this the 20th anniversary of XKCD? Strange that Randall wouldn't make a special comic! 92.92.106.219 18:27, 2 October 2025 (UTC)

Depends upon what you count the start as.

Also, is 20 years special enough to mark..? Maybe 0x20 years! Or 0x2A... 82.132.215.216 19:26, 2 October 2025 (UTC)

My favorite option: "Measure never, cut forever!" Heard Bec Hill say this on the podcast A Problem Squared (don't ask me which episode). Couldn't find much about it online so for all I know she came up with it. It's catchy! --NeatNit (talk) 20:06, 2 October 2025 (UTC)

What about other professions or trades? Is it the number of cuts or number of things cut? Is sawing a series of cuts or just one cut?

• Barber: if comparing hair length counts as measuring, about 1:1 to 1:3 measure:cut ratio, since they sometimes snip-snip-snip a line of hair they're holding between two fingers. If measuring excludes estimating, then they're way to the right of serial killers. Do clippers count as cutting?
• Gardener: probably about the same as barbers; more actual measurement likely.
• Film director: Mostly 'cut', I think.

TimBav (talk) 13:18, 3 October 2025 (UTC)

Barbers basically are serial killers... (Or, as it turns out, lumberjacks, who cut cut cut.) 81.179.195.93 18:38, 3 October 2025 (UTC)

Sawing has to count as just one cut, otherwise the phrase doesn't make sense for carpenters where it originated. --NeatNit (talk) 17:38, 14 October 2025 (UTC)

Here's an exception to the 'Surgeon' category. And another similar one, though not with a physical cutting device. 81.179.195.93 18:19, 4 October 2025 (UTC)

Laproscopic surgery requires many cuts, and I'm not sure, but I think many surgeries require an initial cut to get to the problem and other cuts to fix the problem. Sometimes there are multiple problems requiring multiple cuts (such as in a shooting where the holes need operation. I suppose that could be called multiple surgeries.... But serial killing could be multiple tasks as well. -- 208.38.240.15 (talk) 14:59, 6 October 2025 (please sign your comments with ~~~~)
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