Last updated: July 2026
The calculators produce estimates
SurfSizer's calculators apply published rules of thumb to the details you enter. They are a starting point for a decision, not a measurement of your body or a specification for a board.
Surfboard volume is the clearest example. Two surfers of identical weight and stated ability can be genuinely happy on boards several litres apart, depending on where they surf, how often, what they are used to and what they enjoy riding. A number from this site is something to take to a shaper and discuss, not something to order from.
The same applies elsewhere. Wetsuit thickness recommendations assume typical conditions and a typical session; how you personally feel the cold matters more than any chart. Fin, leash and wax guidance describes common practice, not a rule that holds in every condition.
Where we disagree with a brand, the brand wins
Wetsuit and board sizing varies between manufacturers, and manufacturers revise their charts. The figures here are compiled to be broadly representative. If a brand's own current size chart disagrees with this site for the suit or board you are actually buying, follow the brand, not us — and please tell us so it can be corrected.
This is not safety advice
Nothing on SurfSizer tells you whether it is safe to paddle out. Surfing carries real risk of injury and drowning. Conditions, tides, currents, crowds, your own ability on the day and local knowledge decide that, and no calculator has access to any of it.
Wetsuit thickness guidance in particular should not be read as protection against cold-water immersion or hypothermia. It describes what people commonly wear to stay comfortable in a normal session in given water temperatures. It is not a survival calculation, and it does not account for wind chill after a wipeout, unexpected immersion, or how long you might end up in the water if something goes wrong. If you surf cold water, get proper advice on cold-water safety from a qualified source.
Not professional advice
SurfSizer is an independent site run by an engineer who builds web tools, as explained plainly on the About page. It is not run by a shaper, a wetsuit manufacturer, a surf coach or a medical professional, and nothing on it constitutes professional, medical or commercial advice. Decisions about equipment you buy, and about your own safety in the water, remain yours.
Accuracy and availability
The information here is offered in good faith and the calculation logic is published on the pages themselves so it can be checked. Even so, no guarantee is made that the content is complete, current or free of error, and the site is provided as is, without warranties of any kind, express or implied. To the fullest extent permitted by law, no liability is accepted for any loss or damage arising from reliance on anything published here — including any purchase made on the basis of a figure from a calculator.
No guarantee is made that the site will be available without interruption or free of technical faults.
Brands and trademarks
Brand, manufacturer and product names referred to on this site belong to their respective owners and are used for identification and descriptive purposes only. SurfSizer is independent and is not affiliated with, authorised by, endorsed by or sponsored by any surfboard shaper, wetsuit manufacturer, fin brand or retailer mentioned anywhere on the site.
External links
Where this site links to another website, that link does not imply endorsement of its content, products or accuracy. We do not control third-party sites and are not responsible for what they publish or how they handle your data.
Corrections
If a figure here looks wrong, we would rather hear about it than not. Email hello@surfsizer.com with the page and what you believe the correct value should be, and it will be looked into. Genuine errors get fixed and the page's updated date changes accordingly.