# What surfboard volume do I need?

Suggests a surfboard volume in liters from your weight and surfing level with the Guild Factor (weight in kg × factor), as a range and a middle value, or from a factor you choose.

- Page: https://www.acalculator.org/sports/surfboard-volume-calculator
- JSON spec: https://www.acalculator.org/sports/surfboard-volume-calculator.json
- Version: de770c62e44b

## Default answer

Example with the default inputs (Your weight 170 lb, Your level Average to above-average, typical fitness (0.36–0.38)): At 170 lb and a Guild Factor of 0.36 to 0.38 (middle 0.37), your surfboard volume is about 28.5 liters.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| w | Your weight | Your body weight, in your wetsuit if you surf in a thick one. |
| lvl | Your level | Your surfing level and fitness, which sets the Guild Factor range. |
| gf | Guild Factor | Board liters per kilogram of body weight, such as 0.4. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| volume | Board volume (liters) | Weight in kg × the middle of the Guild Factor range. |
| low | Low end (liters) | Weight in kg × the low end of the range: for warm water and good waves. |
| high | High end (liters) | Weight in kg × the high end of the range: for poor waves or a thick wetsuit. |
| kg | Weight in kg | Your weight in kilograms. |
| range | Guild Factor | The Guild Factor used, or its range. |

## Method

Board volume (liters) = weight (kg) × Guild Factor; the range uses the low and high factors of your level.

## Assumptions

- One liter of board volume per kilogram is the Guild Factor’s unit: the factor is liters ÷ kilograms.
- The headline uses the middle of your level’s range.
- Typed values are read as the exact decimals typed, so a volume exactly half a tenth rounds up.

## Worked examples

1. w = 92.986436, lvl = weekend gives high = 39.054303, low = 35.334846, volume = 37.194574. Source: Lost Surfboards by Mayhem, What’s Your Guild Factor? Surfboard Volumes Explained (Guild Factor = volume in liters ÷ body weight in kg; 0.34–0.36 advanced and very fit, 0.36–0.38 typical fitness and average to above-average skill, 0.38–0.42 lower fitness and weekend surfers, 0.40–0.50 novices or extreme conditions; © Whitney Guild 2013), https://lostsurfboards.net/whats-your-guild-factor-surfboard-volumes-explained/ (retrieved 2026-10-02) (Matt Biolos: 205 lbs, 39 liters, GF .42).
2. w = 70, lvl = advanced gives low = 23.8, high = 25.2, volume = 24.5, range = 0.34 to 0.36 (middle 0.35). Source: Lost Surfboards by Mayhem, What’s Your Guild Factor? Surfboard Volumes Explained (Guild Factor = volume in liters ÷ body weight in kg; 0.34–0.36 advanced and very fit, 0.36–0.38 typical fitness and average to above-average skill, 0.38–0.42 lower fitness and weekend surfers, 0.40–0.50 novices or extreme conditions; © Whitney Guild 2013), https://lostsurfboards.net/whats-your-guild-factor-surfboard-volumes-explained/ (retrieved 2026-10-02).
3. w = 81.646627, lvl = custom, gf = 0.45 gives volume = 36.740982, low = 36.740982, range = 0.45. Source: Lost Surfboards by Mayhem, What’s Your Guild Factor? Surfboard Volumes Explained (Guild Factor = volume in liters ÷ body weight in kg; 0.34–0.36 advanced and very fit, 0.36–0.38 typical fitness and average to above-average skill, 0.38–0.42 lower fitness and weekend surfers, 0.40–0.50 novices or extreme conditions; © Whitney Guild 2013), https://lostsurfboards.net/whats-your-guild-factor-surfboard-volumes-explained/ (retrieved 2026-10-02).

## FAQ

### How do I calculate surfboard volume?

Multiply your weight in kilograms by your Guild Factor. A 205 lb (93 kg) weekend surfer with a factor of 0.42 needs about 93 × 0.42 = 39 liters, which is the example Lost Surfboards gives for shaper Matt Biolos.

### What is the Guild Factor?

A ratio devised by Whitney Guild: board volume in liters ÷ body weight in kilograms. His table runs from 0.34 to 0.36 for advanced, very fit surfers up to 0.40 to 0.50 for novices or extreme conditions. A higher factor means more foam for your weight.

### Should I pick the low or the high end of my range?

The table's own advice: in warm water and good waves, the low end; in poor waves, crowded lineups or a thick wetsuit, the high end. The headline is the middle of the range.

### Why does fitness matter, not just skill?

Paddling a smaller board takes strength and stamina. The Guild table groups surfers by fitness as well as skill, so a skilled surfer who surfs only on weekends is put at 0.38 to 0.42, not with the very fit advanced surfers.

### Do I use my weight in pounds?

You can type pounds; the calculator converts to kilograms first (1 lb = 0.45359237 kg), because the Guild Factor is liters per kilogram. 170 lb is 77.1 kg, so at 0.37 that is about 28.5 liters.

### Is volume the only thing that matters?

No. Length, width, thickness and where the foam sits change how a board paddles and turns. Two boards of the same volume can feel very different, so use the volume as a starting point when you compare boards.

## Sources

- Lost Surfboards by Mayhem, What’s Your Guild Factor? Surfboard Volumes Explained (GF measures the ratio between body weight and volume in liters; 0.34–0.36 advanced, extremely fit; 0.36–0.38 typical fitness, average to above-average skills; 0.38–0.42 lower fitness, weekend warriors; 0.40–0.50 novices or extreme conditions; low end for warm water and good waves, high end for poor conditions or thick wetsuits; example: Matt Biolos, 205 lbs, 39 liters, GF .42; © Whitney Guild 2013). https://lostsurfboards.net/whats-your-guild-factor-surfboard-volumes-explained/ (retrieved 2026-10-02)