Surfers' weight to board thickness, length and width ratio

Is there a “hard-and-fast” rule to follow?

Also, are there guidelines for matching these variables when a surfers weight is known?

Thanks in advance for your input. This site looks REALLY cool!


PS - I’ve wanted to shape boards for 15 years and I’m thinking about taking it up for a serious hobby.

11.5 : 3 harf and fast rule of thompf… ambrose… surly somebody can validate that precicenicity

no offense but as vague questions go yours has to be the vaguest…search the archives…there are no hard and fast rules

Hey Action,

Welcome to Swaylocks…

Although there aren’t any real hard-fast-rules - there are def some loose guidelines. A lot of board companies have a size chart and here is a good example of one from NA

Again they’re loose guidelines - For example I would particularly disagree with NA’s site (and probably just about everyone, haha) in regards to their fish sizing. I also think most people ride their shortboards way too short.

15 years is way too long to wait - grab a blank and start mowing into that sucker!!!

Best luck,


I use the 45 belly button rule. If you are over 45 years old the board should float up to your belly button when sitting. Mike

I'm thinking about taking it up for a serious hobby.

Just remember to keep it serious :slight_smile:

Okay, now that really made me laugh. A nice relief from the more serious conversations… But the more I think about it - it’s also really not a bad gauge.



There are no "hard and fast " rules, but some observations might be helpful.

Skill matters. A big guy can surf a short,thin board if he’s skillful enough.

Flat bottoms tend to plane on top of the water.

“V” or belly bottoms displace water, and plow through the water more than a flat one.

Thinner boards react quicker than thicker boards.

Lighter boards react quicker than heavier boards.

Lighter boards are more vulnerable to surface chop in the water.

Big Boys with average surfing abilities tend to like big boards that float well. (there are many exceptions)

Shorter boards have less rail engaging the wave, hence less drag, hence more speed.

Just a few things I’ve noticed. BUT, I know that if you talk to 5 shapers, you’ll get 6 opinions.

Read some books. Look at some videos. Step on the gas pedal of your imagination and go.

Surfboard design has infinite possibilities. The beauty is: we are all free to discover any number of those possibilities. So go ahead: Start shaping! and let us know about the results. Doug


11.5 : 3 harf and fast rule of thompf… ambrose… surly somebody can validate that precicenicity


not a word of that made sense to me…

But don’t worry “action now”, I’m sure SOMEONE here can help you…WELCOME, by the way ! [I’m fairly new here myself!]

my .02 : -

I read where reno abellira once asked dick brewer what the smallest board he could ride was, whereupon brewer apparently laid him on his back, traced around him and said here’s your answer [or words to that effect].

Of course, that MAY be oversimplifying things, there are considerations like the person’s fitness, waves surfed, paddling ability, height and weight of the person…and their ‘type of board’ personal preferences.

It’s actually something I’ve occassionally pondered , in terms of shorter ,wider, thinner boards - versus longer, narrower , thicker boards…and the variations in between.

   anyway, it may be interesting to hear people's experiences / preferences... 


Rather than searching for the smallest board I can ride, at the moment my quest is to find the longest, easiest paddling board that I can still duck dive for winter! (I only weigh 150lbs.) But as there is no easy way to quantify overall board volume and location and nose shape and all the other factors that go into being able to get a board under water, I’ve just got to keep trying different boards. If anyone has general comments on this issue, I’d love to read them though!

Thanks HerbB and others that gave their input. It appears that there are no hard-and-fast rules in an “in-excact science/art.”

Sounds like this bunch wants you to do your homework before posting. I’ll keep that in mind before posting next time.



That’s a good one… I could not stop thinking about the attached Far Side Cartoon.

I have defiently found myself adding a bit to my boards as I have gotten older. Just easier to get into the waves. I will take out a thin chip now and thin if the waves are right.


Yeah the archives are really good source - dig into them but don’t sweat asking questions.

Look at the most recent posts - more than half aren’t even related to design. Your’s was…



yes no hard rules no fast rules ,Guidelines are arbitrary and changed by individuals at whim,you are welcome to all the input you can glean ,wanting is good doing is better, there is a serious hobby:swaylocks…I was wrong no one was surly or precise Hark to try to thwart the creative growth charts are made authoritativly to aid in the simplification at point of purchase…example shoe sizes vary as do clothingsizing measure body part ,foot ,neck ,waist. hand then try on,verdad? then the alteration process begins …ambrose…fun in procrastination 15 years is good…serious is acceptable in some circles even shaping circles…circles are hard to get perfect

no hard and fast rule…but bigger bloke always = bigger board (esp wrt width) — smaller guys can definitely get away with less foam. Don’t surf a board that sinks further than your shoulders when sitting on it…I tried a lighter friends board the other day and just ended up getting splashed by chop in the face.


You may want to check out They have a Size Chart for each of their shapes. It shows specs (length, nose, width, tain, thickness) for each Harbour model based on weight. If nothing else, this can put you in a general direction for different types of boards.

Kinda depends on the size and power of your winter waves!

Here at OceanBeach SF, most 155lbs’ers consider a 6’8" x 18.5 maximum sizing for pushing under 6’ waves. Different for different spots. A 4/3 wetsuit year round doesn’t help getting under the whitewater.

But kind of an exercise on doom, I’d say. Why worry about duckdiving? When it’s really breaking hard at 5-7’ most guys can’t hold on to their chip tris, except for the competition pros, who surf 6 days a week on 6’ x 18" x 2.15 sinkers.

Heck, most guys get out with any size board, from 10’ logs to semi/mini guns to pocket rockets and fish.