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Convert pounds per square inch (PSI) to standard atmospheres (atm) instantly. Accurate pressure conversion for automotive, scuba diving, industrial, and scientific applications.
Formula: Atmospheres = PSI × 0.068046 | PSI = Atmospheres × 14.696
Reference table of frequently used PSI to atmosphere conversions across automotive, diving, industrial, and everyday applications. Values calculated using the factor 1 atm = 14.696 PSI.
| PSI | Atmospheres (atm) | Real-World Context |
|---|---|---|
| 0 PSI | 0 atm | Absolute vacuum (no pressure) |
| 5 PSI | 0.3402 atm | Low-pressure pneumatic tools |
| 10 PSI | 0.6805 atm | Bicycle tire (road bike minimum) |
| 14.696 PSI | 1.0000 atm | Standard atmospheric pressure at sea level |
| 20 PSI | 1.3609 atm | Low-pressure industrial air systems |
| 30 PSI | 2.0414 atm | Typical passenger car tire pressure |
| 35 PSI | 2.3816 atm | SUV / truck tire pressure |
| 44 PSI | 2.9940 atm | Scuba diving at 20 meters depth (absolute) |
| 50 PSI | 3.4023 atm | Residential water pressure |
| 60 PSI | 4.0828 atm | Standard municipal water supply |
| 80 PSI | 5.4437 atm | Commercial water pressure systems |
| 100 PSI | 6.8046 atm | Pressure washer (low setting) |
| 150 PSI | 10.2069 atm | Compressed air systems |
| 200 PSI | 13.6092 atm | Hydraulic brake systems |
| 300 PSI | 20.4138 atm | Scuba tank (low reserve) |
| 500 PSI | 34.0230 atm | Industrial hydraulic systems |
PSI (pounds per square inch) is a unit of pressure commonly used in the United States and other countries that follow the imperial measurement system. It quantifies the amount of force (in pounds) applied over an area of one square inch. PSI is the standard unit for tire pressure, hydraulic systems, compressed gas cylinders, and water pressure in residential and commercial plumbing. In engineering contexts, you may encounter PSIG (gauge pressure, relative to atmosphere) and PSIA (absolute pressure, including atmospheric pressure).
ATM (standard atmosphere) is a unit of pressure defined as exactly 101,325 Pascals, which equals 14.696 PSI, 1.01325 bar, or 760 mmHg. It represents the average atmospheric pressure at sea level at a temperature of 15 degrees Celsius. The atmosphere is widely used in chemistry and physics, particularly in gas law calculations (Boyle's Law, ideal gas law), defining standard temperature and pressure (STP), and expressing underwater diving depths.
Converting between PSI and ATM is essential when working across American engineering standards (which use PSI) and international scientific conventions (which use ATM or Pascals). Scuba divers, automotive technicians, HVAC professionals, and chemical engineers regularly need to translate between these two pressure units to ensure accurate and safe operations.
atm = PSI × 0.068046 or atm = PSI ÷ 14.696
Since 1 standard atmosphere equals exactly 14.696 PSI, you divide any PSI value by 14.696 (or multiply by its reciprocal, 0.068046) to get the equivalent pressure in atmospheres. The reverse conversion is PSI = atm × 14.696.
Convert 32 PSI to atmospheres:
Result: 32 PSI = 2.1775 atm
Convert 3,000 PSI (full scuba tank) to atmospheres:
Result: 3,000 PSI = 204.138 atm
Convert 55 PSI (typical home water pressure) to atmospheres:
Result: 55 PSI = 3.7425 atm
For a quick approximation, divide the PSI value by 15. This gives a result within about 2% of the exact answer. For example, 45 PSI ÷ 15 = 3.0 atm (exact: 3.062 atm). This shortcut is handy when you need a rough estimate in the field without a calculator.
| Vehicle Type | Typical PSI | ATM (Gauge) | ATM (Absolute) |
|---|---|---|---|
| Passenger Car | 30-35 PSI | 2.04-2.38 atm | 3.04-3.38 atm |
| SUV / Light Truck | 35-40 PSI | 2.38-2.72 atm | 3.38-3.72 atm |
| Heavy Truck | 80-100 PSI | 5.44-6.80 atm | 6.44-7.80 atm |
| Racing / Performance | 20-28 PSI | 1.36-1.91 atm | 2.36-2.91 atm |
| Bicycle (Road) | 80-130 PSI | 5.44-8.85 atm | 6.44-9.85 atm |
| Depth / Scenario | PSI (Absolute) | ATM (Absolute) |
|---|---|---|
| Surface (sea level) | 14.7 PSI | 1.0 atm |
| 10 meters (33 ft) | 29.4 PSI | 2.0 atm |
| 20 meters (66 ft) | 44.1 PSI | 3.0 atm |
| 30 meters (99 ft) | 58.8 PSI | 4.0 atm |
| 40 meters (131 ft) - recreational limit | 73.5 PSI | 5.0 atm |
| Full scuba tank | 3,000 PSI | 204.1 atm |
| Application | Typical PSI | ATM Equivalent |
|---|---|---|
| Residential HVAC (low side) | 60-85 PSI | 4.08-5.78 atm |
| HVAC (high side) | 150-300 PSI | 10.21-20.41 atm |
| Compressed air (shop) | 90-150 PSI | 6.12-10.21 atm |
| Hydraulic systems | 1,000-5,000 PSI | 68.0-340.2 atm |
| Steam boiler | 15-300 PSI | 1.02-20.41 atm |
| Natural gas pipeline | 200-1,500 PSI | 13.61-102.07 atm |
Tire pressure is measured in PSI in the US but in bar or atm in many other countries. Correct pressure ensures fuel efficiency, even tire wear, and safe handling. Converting between PSI and atm helps international drivers and technicians work with global specifications.
Dive computers and tank gauges use PSI in the US, while dive tables and physics calculations use ATM. Understanding that every 10 meters of seawater adds 1 atm (14.696 PSI) is critical for safe dive planning, decompression schedules, and gas consumption calculations.
Hydraulic presses, pneumatic tools, and steam systems operate at specific PSI ratings. When referencing scientific standards or international equipment manuals that use atmospheres, accurate conversion prevents equipment damage, production errors, and safety hazards.
HVAC technicians measure refrigerant pressures in PSI using manifold gauges. Thermodynamic calculations and refrigerant property charts sometimes reference pressures in atmospheres. Accurate conversion ensures proper system charging, leak detection, and efficient operation.
The most common mistake is confusing PSIG (gauge) with PSIA (absolute). A tire at 32 PSIG is actually 46.7 PSIA (32 + 14.696). When converting to ATM for scientific calculations, you usually need PSIA. Always check which reference point your measurement uses.
While 1 atm is approximately 14.7 PSI, the exact value is 14.69595 PSI (often rounded to 14.696). For rough estimates, 14.7 works fine. For scientific or engineering calculations requiring precision, use the full value to avoid compounding rounding errors.
While 1 atm and 1 bar are close in value (1 atm = 1.01325 bar), they are not identical. At low pressures the difference is negligible, but at high pressures it becomes significant. Always verify which unit is specified before converting.
Standard atmospheric pressure (1 atm) is defined at sea level and 15 degrees Celsius. At higher altitudes or extreme temperatures, actual atmospheric pressure differs. If you are converting gauge pressure to absolute at a high-altitude location, the atmospheric offset is less than 14.696 PSI.
Pressure gauges may display PSI, kPa, bar, or atm depending on the manufacturer and region. Before performing any conversion, verify the unit on your gauge. Misreading kPa as PSI (or vice versa) leads to conversions that are off by a factor of nearly 7.
One standard atmosphere (1 atm) equals exactly 14.696 PSI (pounds per square inch). This value is defined as the average atmospheric pressure at sea level at 15 degrees Celsius. Conversely, 1 PSI equals approximately 0.068046 atm.
To convert PSI to atmospheres, divide the PSI value by 14.696, or equivalently multiply by 0.068046. The formula is: atm = PSI x 0.068046. For example, 30 PSI equals 30 x 0.068046 = 2.04138 atm.
PSIG (pounds per square inch gauge) measures pressure relative to atmospheric pressure, where 0 PSIG equals 1 atm. PSIA (pounds per square inch absolute) includes atmospheric pressure in the measurement. The relationship is PSIA = PSIG + 14.696. When converting to atm, you typically work with PSIA values.
Underwater pressure increases by approximately 1 atm (14.696 PSI) for every 10 meters (33 feet) of depth. At 30 meters, a diver experiences 4 atm of absolute pressure. Scuba tank pressure is measured in PSI, typically filled to 3,000 PSI (204 atm), so understanding the PSI-to-atm relationship is critical for dive planning and safety.
Atmospheric pressure decreases with altitude. At sea level, pressure is 14.696 PSI (1 atm). At 5,000 feet elevation, it drops to about 12.2 PSI (0.83 atm). At 10,000 feet, it is roughly 10.1 PSI (0.69 atm). This reduction affects engine performance, cooking times, and human physiology.
Most passenger car tires are inflated to 30-35 PSI (2.04-2.38 atm) as recommended by manufacturers. This is gauge pressure (PSIG), meaning it is above atmospheric pressure. The absolute pressure inside the tire is actually 44.7-49.7 PSIA (3.04-3.38 atm) when you add the 14.696 PSI of atmospheric pressure.
In scientific contexts, the atmosphere (atm) is more commonly used, especially in chemistry for gas law calculations and defining standard conditions (STP = 1 atm, 0 degrees Celsius). PSI is more common in engineering and industrial applications, particularly in the United States for hydraulic systems, pneumatics, and tire pressure.
To convert atmospheres back to PSI, multiply the atm value by 14.696. The formula is: PSI = atm x 14.696. For example, 3 atm equals 3 x 14.696 = 44.088 PSI. This is the inverse of the PSI-to-atm conversion factor.
This PSI to ATM converter is provided for informational and educational purposes only. While we strive for accuracy, always verify critical pressure measurements with calibrated instruments. Do not rely solely on online converters for safety-critical applications such as diving, industrial pressure systems, or medical equipment.