Surfboard Volume Calculator: Ideal Litres for Your Weight and Level
Find your ideal surfboard volume in litres from weight, ability, fitness, age, waves, how often you surf and your wetsuit. Estimate a board’s volume from its dimensions and board type, compare it with your target, and see a volume chart by weight and level.
How it works
Volume (L) = weight (kg) × ability ratio (beginner 1.0, novice 0.7, intermediate 0.45, advanced 0.38, expert 0.34) × fitness (+8% / −5%) × waves (+10% / −8%) × age (40+ +6%, 50+ +12%, 60+ +18%) × frequency (−3% to +10%) + wetsuit (0–3 L) · Range = ± 5% · Board litres ≈ length (in) × width (in) × thickness (in) × fill factor × 0.016387 (fill 0.48 step-up, 0.50 shortboard, 0.53 hybrid, 0.54 fish, 0.56 mid-length, 0.58 longboard, 0.72 soft-top)
Volume in litres decides how a surfboard floats and paddles, so shapers print it on most boards. Length alone says little: a 5′10″ shortboard and a 5′10″ fish can differ by ten litres. The usual guide is the guild factor, litres per kilogram of body weight. Beginners want about a litre per kilo or more so the board is stable and easy to stand on. Intermediates ride around 0.4–0.5, and the best surfers go as low as 0.33 so the board stays loose. This calculator starts from that ratio, then adds foam for lower fitness, weak waves, age over 40, surfing only now and then, and a thick wetsuit. It takes foam away for very fit surfers, powerful waves and surfing several times a week. The board check estimates litres from the dimensions with a fill factor for the board type, because a fish or a foamie fills more of its outline box than a pointy shortboard. If you know the printed volume, enter it and it is used instead. The tables show the volume for every level at nearby weights, and the litre range for each board type at your weight.
Worked example
A 78 kg, 35-year-old intermediate of average fitness who surfs about once a week in average waves, in boardshorts: 78 × 0.45 = 35.1 L, with no other adjustments, so about 35 L (33–37 L), or 0.45 L/kg. A 6′0″ × 20.5″ × 2.6″ shortboard has an outline box of 72 × 20.5 × 2.6 = 3,837.6 in³. With a 0.50 fill factor that is 1,918.8 in³ × 0.016387 ≈ 31.4 L, about 3.7 L (11%) short of the target. The same surfer in a 4/3 wetsuit in winter would want about 37 L.
Frequently asked questions
Is more volume always easier?
Up to a point. Too much foam is hard to duck-dive, sits on top of the wave and feels stiff in turns. Match the type of board to the waves, then fine-tune the volume.
How much does a wetsuit change things?
A thick wetsuit adds weight once it is wet and makes paddling harder, so many surfers ride 1–3 L more in winter. Choose your wetsuit under More options and the calculator adds 1 L for a 3/2, 2 L for a 4/3 and 3 L for a 5/4.
How accurate is the volume estimate from dimensions?
Usually within about 10% for common shapes. Rail shape, rocker and foil change the real figure, and the shaper’s design file gives the exact number. That is why you can type the printed volume in under More options.
How many litres does a beginner need?
About a litre per kilogram or more, so 70 L or more for a 70 kg adult. That usually means a soft-top or a longboard. Once you can catch unbroken waves and turn, step down towards 0.6–0.7 L/kg.
What is a guild factor?
It is the board’s volume divided by the surfer’s weight, in litres per kilogram. It lets surfers of different weights compare boards. The calculator shows your target guild factor and the guild factor of the board you entered.
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This calculator is for educational purposes. Double-check important results before acting on them.