freediving weight calculator

Why proper weighting matters in freediving

Weighting is one of the most important setup choices in freediving. Too little lead makes it hard to descend, increases effort, and can spike your heart rate. Too much lead does the opposite: it may feel easy on the way down, but it increases risk near the surface where your wetsuit regains buoyancy.

The goal is not to be “as heavy as possible.” The goal is to be appropriately weighted for your wetsuit, water type, body composition, and planned depth. This calculator gives you a practical starting point.

How this freediving weight calculator works

The estimate combines several buoyancy factors:

• Body weight: larger divers generally need more lead, all else equal.
• Water type: salt water is more buoyant than fresh water.
• Wetsuit type and thickness: thicker neoprene means more flotation at the surface.
• Body composition: leaner divers often need slightly more lead than divers with higher body fat.
• Target neutral depth: deeper neutral depth usually means less total lead.

The output is intentionally shown as a range because real-world conditions vary: salinity, suit age, lung fill, equipment, and individual technique all influence buoyancy.

How to dial in your final weight in the water

1) Start conservative

Begin with the lower end of the recommended range and perform a controlled buoyancy check with a buddy and proper supervision.

2) Check at your planned neutral depth

If your target is recreational depth, many divers aim for neutral around 8-12 meters. Technical and deep divers may choose a different target based on training and conditions.

3) Adjust in small increments

Change weight by 0.5 kg (or 1 lb) at a time. Big jumps make it harder to understand what actually improved your setup.

4) Re-check whenever conditions change

• Switching from pool to ocean
• Changing from 3 mm to 5 mm suit
• Adding/removing hood, gloves, or booties
• Significant body weight changes

Common freediving weighting mistakes

• Copying someone else’s setup: two divers of the same body weight can need very different lead.
• Ignoring wetsuit compression: neoprene loses buoyancy with depth, so surface feel can be misleading.
• Overweighting for easy duck dives: this can reduce safety margin near the surface.
• Not reassessing over time: suit wear, training, and body composition changes matter.

Quick rule-of-thumb reference

These rough starting points are common, but always validate in water:

• No suit in warm water: often very light lead or none
• 3 mm full suit: moderate lead depending on body type and salinity
• 5 mm two-piece suit: significantly more lead than a 3 mm one-piece
• Fresh water: usually less lead than ocean for the same equipment

Safety note

This tool is for education and estimation only. It is not a substitute for professional instruction, a proper buoyancy assessment, or supervised training. Never freedive alone. Practice with a qualified buddy and follow recognized freediving safety protocols.