Scuba Weight
Calculate scuba weight. 10% saltwater, 8% freshwater. 3mm vs 7mm wetsuits. 130 ft recreational limit. PADI, SSI, DAN.
📋 Quick Examples — Click to Load
📊 Water Type
8% vs 10% body weight
📈 Wetsuit Buoyancy
Extra weight needed
🍩 Tank Buoyancy
Aluminum vs steel
📊 Depth Limits
Recreational limits (ft)
For educational and informational purposes only. Verify with a qualified professional.
Scuba weight: salt water ~10% body weight, fresh ~8%. Wetsuit adds buoyancy—3mm +2–4 lb, 7mm +6–10 lb. Aluminum tank +1.6–2.7 lb when empty; steel -3 to -9 lb. 130 ft recreational limit. PADI, SSI, DAN standards.
Sources: PADI, SSI, DAN.
Key Takeaways
- • Salt water 10%, fresh 8% body weight as starting point.
- • Wetsuit thickness adds buoyancy: 3mm +2–4 lb, 7mm +6–10 lb.
- • Aluminum tank adds weight when empty; steel is negative.
- • 130 ft recreational limit. Do weight check at safety stop.
Did You Know?
How Does Scuba Weight Work?
Buoyancy Basics
Salt water is denser—10% body weight. Fresh 8%. You need enough weight to descend and stay neutral at safety stop. Too much = hard to ascend. Too little = can't descend.
Wetsuit Buoyancy
Neoprene traps gas—wetsuits float. 3mm adds ~2–4 lb need, 5mm ~4–6, 7mm ~6–10. Drysuits need more. Always do a weight check in new gear.
Tank Factor
Aluminum tanks float when empty (+1.6–2.7 lb). Steel sinks (-3 to -9 lb). At end of dive, aluminum is lighter—you may need more weight at start for empty-tank buoyancy.
Expert Tips
Weight by Conditions
| Condition | 160 lb diver |
|---|---|
| Salt, 3mm | ~19 lb |
| Salt, 7mm | ~24 lb |
| Fresh, 5mm | ~18 lb |
Frequently Asked Questions
How much weight do I need for scuba diving?
Salt water: ~10% of body weight. Fresh water: ~8%. Add for wetsuit buoyancy: 3mm adds ~2–4 lb, 7mm adds ~6–10 lb. Aluminum tank adds 1.6–2.7 lb negative when empty; steel 3–9 lb. Start with 10% and adjust.
What is the 10% rule for saltwater?
Salt water is denser than fresh. 10% body weight is the starting point for saltwater. 8% for freshwater. Example: 160 lb diver → 16 lb salt, 13 lb fresh. Adjust for exposure suit and tank.
How does wetsuit thickness affect weight?
3mm wetsuit adds buoyancy—need 2–4 lb extra weight. 5mm: 4–6 lb. 7mm: 6–10 lb. Drysuits need more. The thicker the suit, the more weight to compensate for neoprene floatation.
What about tank buoyancy?
Aluminum 80: +1.6 to +2.7 lb when empty (floats). Steel: -3 to -9 lb (sinks). Full tanks are negative; empty aluminum can float. Account for tank type in total weight.
What is the recreational depth limit?
130 ft (40 m) is the recreational limit per PADI/SSI. Most training dives 60–100 ft. DAN recommends conservative profiles. Never exceed your certification limits.
How do I do a proper weight check?
At safety stop (15 ft), with 500 psi remaining, you should be neutrally buoyant. If you sink, remove weight. If you float up, add weight. PADI/SSI teach this in OW certification.
Key Statistics
Official Data Sources
⚠️ Disclaimer: This calculator is for educational purposes only. Always do a proper weight check. Never exceed your certification limits. Consult PADI/SSI professionals. Not professional diving advice.