Surfboard volume calculator

Start with volume, then length. Volume comes from your weight, ability and fitness, and length mostly from your height and the type of board. For example, a 75kg intermediate surfer who surfs once or twice a week usually starts around 32.5 to 35.5 litres in a shortboard and 41 to 46.5 litres in a mid-length. Use the calculator above for your own numbers, then Joe refines them at a free consultation.

This calculator uses the guild factor method: your weight in kilograms multiplied by a factor for your ability and the type of board, then nudged up or down a few percent for how often you surf, your age and the waves you ride. The factors sit inside the ranges commonly published for this method. The board's actual volume comes from its length, width, thickness and every curve in between.

There is no single right number. Two surfers of the same weight can need very different boards: a fit surfer in the water four days a week can ride less foam than someone who surfs twice a month. Most adult shortboards land somewhere in the high 20s to high 30s of litres, mid-lengths more, and longboards far more.

No. Volume tells you how much foam there is, not where it is. Two boards with the same litres can feel nothing alike. The best single piece of information is what you ride now and what you would change about it. Bring it in, or bring its dimensions, and Joe works out the length, width, thickness and volume with you. More in how to size a custom surfboard.

Our outlines are sized from your height first: the Blade about 1 inch shorter than you. Your height turns a volume into a sensible starting length.

Weight sets the volume and height sets the starting length. From the size chart: a 6'0" (183 cm) intermediate surfer starts around 5'11" to 6'1" in a shortboard and 6'4" to 6'7" in a mid-length, and at 80 kg needs about 34.5 to 38 litres in a shortboard. Joe sets the final numbers at the free consultation.

Often, yes. Seven foot is mid-length territory (roughly 6'4" to 7'6"), and most surfers at the beginner stage progress faster on more foam, which is why the calculator suggests a mid-length for them. The Asym | Mid is made for points and A-frames from 3ft to 6ft.

For a 90 kg intermediate surfer who surfs once or twice a week in everyday beach breaks, the size chart gives about 39 to 42.5 litres in a shortboard, 42.5 to 47.5 in a fish or twin, 49 to 55.5 in a mid-length and 76 to 87 in a longboard. A beginner at 90 kg starts around 51 to 57.5 litres in a shortboard.