Free tool
Enter your weight and how you surf. You get a litre range to shop in — not a single number, because every shaper's calculator disagrees with every other by ten to fifteen percent, and pretending otherwise would be dishonest. Below the tool: what the wrong volume actually looks like when you film yourself.
Ability
Age
Fitness
Usual waves
Recommended range
34–44 litres
This is the range where most riders plateau on a board that is slightly too small for their wave count. If in doubt, go up two litres, not down.
Base factor band, in litres per kilogram of body weight: beginner 0.60–0.90 · intermediate 0.42–0.55 · advanced 0.36–0.42 · expert 0.33–0.36.
Additive adjustments to both ends of the band: age 40–49 +0.02, age 50+ +0.04; average fitness +0.02, out of the water a lot +0.04; small or weak waves +0.03; powerful or hollow waves −0.02 (applied only at advanced and expert level, never for beginners or intermediates).
Recommended range = your weight in kilograms × (low factor + adjustments) to your weight in kilograms × (high factor + adjustments), rounded to whole litres.
These bands are our synthesis of published shaper guides and volume calculators. They are heuristics, not physics: two shapers will give the same rider numbers ten to fifteen percent apart, and both boards will work. Mid-lengths and longboards run far more volume than any of these bands and are chosen on length and outline instead. Treat the range as where to start looking, not as a verdict.
| Weight | Beginner | Intermediate | Advanced | Expert |
|---|---|---|---|---|
| 50 kg | 30–45 | 21–28 | 18–21 | 17–18 |
| 55 kg | 33–50 | 23–30 | 20–23 | 18–20 |
| 60 kg | 36–54 | 25–33 | 22–25 | 20–22 |
| 65 kg | 39–59 | 27–36 | 23–27 | 21–23 |
| 70 kg | 42–63 | 29–39 | 25–29 | 23–25 |
| 75 kg | 45–68 | 32–41 | 27–32 | 25–27 |
| 80 kg | 48–72 | 34–44 | 29–34 | 26–29 |
| 85 kg | 51–77 | 36–47 | 31–36 | 28–31 |
| 90 kg | 54–81 | 38–50 | 32–38 | 30–32 |
| 95 kg | 57–86 | 40–52 | 34–40 | 31–34 |
| 100 kg | 60–90 | 42–55 | 36–42 | 33–36 |
Litres. Add 2–4 litres for 40+, average fitness, or weak waves — or use the calculator above.
We read filmed rides for a living, and volume mistakes have a signature. Most riders blame the board for technique problems and blame their technique for board problems. The footage tells you which one it is, and it's cheaper than a new board.
This is exactly the diagnosis in our sample report: board fine, rider surfing the board instead of the wave.
As a starting range, multiply your weight in kilograms by 0.60–0.90 if you're a beginner, 0.42–0.55 if you're intermediate, 0.36–0.42 if you're advanced, or 0.33–0.36 at expert level, then add a few litres if you're over 40, less fit, or surf weak waves. The calculator on this page does the arithmetic.
Usually yes. More volume means easier paddling, earlier take-offs and more waves per session, which is what accelerates learning. The cost — a board that's harder to turn — doesn't matter until you're turning.
Less than in ocean surfing, because the boat provides the speed. Wakesurf boards are chosen mainly on length relative to rider weight and on the style of riding (surf-style vs skim-style), not on litres.
Film a ride from the side, landscape, whole wave. Under-volumed boards show up as late take-offs and stalling; over-volumed boards as flat, skidding turns. If the board is inside the recommended range and you're still stuck, it's technique — and video will show you exactly which part.
Send one filmed ride. Within 48 hours you get a verdict, a scorecard and the three things to fix first — and one of them will be about the board only if it should be.
Free during our founding launch. No card.