Underwater Pressure Converter
Calculate pressure at different depths in various types of water
Underwater Pressure Calculator
Density: 1025 kg/m³. Standard seawater with 3.5% salinity. Used as reference for most dive tables and calculations.
Diving Considerations:
Recreational diving depth. No decompression needed for standard dive times.
Formula Used:
P = P₀ + ρgh
Where:
P = Total pressure
P₀ = Atmospheric pressure (1 atm = 1.01325 bar)
ρ = Water density (dependent on water type)
g = Gravitational acceleration (9.81 m/s²)
h = Depth
Pressure Effects at Different Depths
| Depth (m) | Pressure (bar) | Pressure (atm) | Effects |
|---|---|---|---|
| 0 | 1.01 | 1.00 | Surface pressure (1 atmosphere) |
| 10 | 2.01 | 1.98 | Air volumes halved from surface |
| 20 | 3.01 | 2.97 | Increased air consumption; nitrogen absorption increases |
| 30 | 4.01 | 3.95 | Common recreational depth limit; mild nitrogen narcosis possible |
| 40 | 5.01 | 4.94 | Maximum recreational limit; moderate nitrogen narcosis |
| 60 | 7.01 | 6.92 | Severe nitrogen narcosis; technical diving only |
| 100 | 11.01 | 10.87 | Professional/commercial diving only; specialized gas mixtures required |
Diving Pressure Facts
- • Every 10 meters of depth in seawater adds approximately 1 bar (14.5 psi) of pressure.
- • At 10 meters depth, the total pressure is about 2 atmospheres (1 atm for air + 1 atm for water).
- • Pressure affects gas volumes according to Boyle's Law: as pressure increases, gas volume decreases proportionally.
- • Saltwater is about 3% denser than freshwater, resulting in slightly higher pressure at the same depth.
- • Pressure units used in diving include: bar, atmospheres (atm), and meters/feet of seawater (msw/fsw).
- • According to Dalton's Law, the pressure of each gas in a mixture is proportional to its concentration.
- • Henry's Law states that the amount of dissolved gas in a liquid is directly proportional to its partial pressure.
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Underwater Depth & Pressure
Current Depth & Pressure:
Air Volume at Depth:
(Decreases with depth due to Boyle's Law)
No-Decompression Limit:
Approximately 200+ min at 10m
(Based on standard tables; consult proper dive tables for accuracy)
Nitrogen Narcosis Risk:
Low (N₂ partial pressure: 1.58 ATA)
(Nitrogen narcosis effects often begin at depths greater than 30m)
Pressure Unit Reference
1 bar = 100,000 Pascals = 14.5038 psi
1 atm = 1.01325 bar = 760 mmHg
1 psi = 0.0689476 bar = 6.895 kPa
1 msw (meter of seawater) = 0.0980665 bar
1 fsw (foot of seawater) = 0.02989067 bar
Diving Safety Reminder
This tool provides general calculations and information only. Always:
- Dive within your training limits
- Use proper dive tables or computers
- Follow safe ascent rates (max 9-10 m/min)
- Plan for safety stops
- Never dive alone
Mobile tip: Swipe left or right on the unit dropdown to quickly change units, or use the arrow buttons
About the Underwater Pressure Converter
Calculate pressure at different depths in various types of water All conversions run instantly in your browser and nothing you enter is sent to a server.
Common Conversion Formulas
| From | To | Formula |
|---|---|---|
| Depth (m) | Pressure (atm) | P = (Depth × ρ × g) / 101325 + 1 (where ρ is density) |
| Depth (m) | Pressure (bar) | P = (Depth × 0.0981) + 1 |
| Depth (ft) | Pressure (psi) | P = (Depth × 0.445) + 14.7 |