How much volume do you actually need
Litres per kilogram by ability, why the number changes with the shape, and how to use volume to filter a used-board search instead of guessing at lengths.
· 3 minute read
Volume replaced length, and nobody told the listings
Two boards can both be 5'10" and be twenty per cent apart in float. Length tells you almost nothing on its own; volume in litres tells you whether the board will paddle for you. That is why volume is the first filter on this site and why a listing without one is worth less to a buyer than a listing with one.
The numbers
Volume scales with your body weight and comes down as your ability goes up. These are litres per kilogram of rider. They are not shortboard figures: a beginner's litres describe a soft top or a funboard, because that is the board a beginner should be on.
- Beginner: 0.90 to 1.00 litres per kg
- Improver: 0.60 to 0.75 litres per kg
- Intermediate: 0.45 to 0.55 litres per kg
- Advanced: 0.35 to 0.40 litres per kg
- Pro: 0.32 to 0.35 litres per kg
So a 75 kg intermediate surfer lands around 34 to 41 litres, and a 75 kg beginner lands near 68 to 75 litres, which is roughly their own bodyweight in litres. That surprises people who have been shown a shortboard table, and it is the number the trade actually uses. Use the calculator on this site rather than doing it in your head.
Shape changes the answer
Both ends of the shape spectrum want more foam than a performance shortboard, for opposite reasons. A groveler or fish needs float to make weak waves work. A step-up needs paddle speed to get into steep ones. Add roughly five per cent for a fish or twin, eight per cent for a step-up, and around a fifth for a midlength.
Longboards, SUPs and foil boards are not chosen by litres per kilogram at all. Length and outline pick those, and any calculator that gives you a confident litre figure for a longboard is making it up.
Adjusting for Bali
- Warm water, no wetsuit: you float slightly less than you do at home in 4 mm of neoprene. Do not size down on arrival.
- Two sessions a day for three weeks: you will be more tired than you plan for. A litre or two extra is not a compromise.
- Reef versus beach break: the same person often wants a smaller board at Uluwatu and a bigger one at Batu Bolong. If you are only buying one board, buy for the wave you will actually surf most.
Common questions
- How many litres should my surfboard be?
- Multiply your weight in kilograms by the factor for your ability: about 0.90 to 1.00 for a beginner, 0.45 to 0.55 for an intermediate, 0.35 to 0.40 for an advanced surfer. A 75 kg intermediate lands around 34 to 41 litres. A beginner of the same weight wants near 68 to 75 litres, which is a soft top or a funboard rather than a shortboard.
- Does volume work the same for a fish or a midlength?
- No. Add roughly five per cent for a fish or twin fin and around a fifth for a midlength. Longboards, SUPs and foil boards are not chosen by litres per kilogram at all.
- What if a used listing does not state the volume?
- Ask the seller to read it off the stringer near the tail, where most manufacturers print it. If it is not printed, the board's model and length give a range rather than a figure, and it should be treated as an estimate.