Ounce or Ounce Force per Square Inch is a low pressure unit which is part of the British and American system of units. 1 ounce per square inch equals 430.922 pascals.

The ozf/in² is used mostly for very low pressure rated equipment such as breather valves or controllers for LP natural gas appliances.

There are exactly 16 oz/in² in 1 psi which duplicates the relationship between pounds and ounces used to measure mass and weight.

To convert 1 oz/in² into other pressure units please use the list of conversion factors below.

Click on a pressure unit link to obtain the equivalent oz/in² conversion value.

To convert different different values of ozf/in² please use our on page pressure calculator.

See how oz/in² are derived from SI units and check whether a unit matches one of the versions of identifying oz/in2.

**Low pressure measurement products**

- Compound +/-200 mb g pressure transmitter with 1/2 BSPT
- Bi-directional -20 to +100 Pa clean room air diff pressure transmitter
- 20 Pa DP range 0-10V output air pressure sensor for building management use
- TSA Precision Pressure Transmitter

## Conversion Factors

- 0.00430922 bar
- 0.0625 psi
- 4.30922 mbar
- 430.922 N/m²
- 430.922 Pa
- 4.30922 hPa
- 0.430922 kPa
- 0.000430922 MPa
- 0.00439418 kg/cm²
- 43.9418 mmH2O 4°C (39.2°F)
- 4.39418 cmH2O 4°C (39.2°F)
- 0.0439418 mH2O 4°C (39.2°F)
- 1.72999 inH2O 4°C (39.2°F)
- 0.144166 ftH2O 4°C (39.2°F)
- 3.23218 mmHg 0°C (32°F)
- 0.323218 cmHg 0°C (32°F)
- 0.127251 inHg 0°C (32°F)
- 3.23218 Torr
- 3232.18 mTorr
- 0.00425287 atm
- 0.00439418 at
- 4309.22 dyn/cm²
- 1 oz/in²
- 3232.18 µHg 0°C (32°F)
- 0.0000279018 tsi (uk, long)
- 0.00003125 tsi (usa, short)
- 0.0045 tsf (usa, short)
- 9 psf
- 4.39418 g/cm²

*Please note that the conversion factors above are accurate to 6 significant figures.*

**Low pressure measurement products**

- 3 wire 4 to 20mA pressure transmitter to measure 100 mbar
- Using 25 mbar DP sensor on vacuum below 0.2 bar absolute
- Four cleanroom zones monitoring system to measure overpressure, temperature & humidity
- Bi-directional -20 to +100 Pa clean room air diff pressure transmitter

## Derivation

The calculation below shows how the pressure unit Ounce per Square Inch (oz/in²) is derived from SI Units.

#### Formula

- Pressure = Force / Area
- Force = Mass x Acceleration
- Acceleration = Distance / (Second x Second)

#### SI Units

- Mass: kilogram (kg)
- Length: metre (m)
- Time: second (s)
- Force: newton (N)
- Pressure: pascal (Pa)

#### Input Values

- 1 Ounce = 0.02834952313 kg
- 1 Inch = 0.0254 m
- 1 Square Inch = 0.0254 m x 0.0254 m = 0.00064516 m²
- Acceleration = Standard Gravity = 9.80665 m/s²

#### Calculation

- 1 Ounce Force = 0.02834952313 kg x 9.80665 m/s² = 0.278013851 N
- 1 oz/in² Pressure = 0.278013851 N / 0.00064516 m² = 430.9223309 Pa

**Low pressure measurement products**

- LEX1 (Ei) High Accuracy Digital Pressure Gauge
- ATEX approved negative 10 mbar vacuum pressure transmitter
- DMP331P Hygienic Flush Pressure Transmitter
- 20 Pa DP range 0-10V output air pressure sensor for building management use

## Alternate Descriptions

These are the different versions used for identifying oz/in² that you may find elsewhere.

- Ounce per Square Inch
- Ounce Force per Square Inch
- Ounces per Square Inch
- Ounces Force per Square Inch
- oz/in²
- ozf/in²
- oz/in^2
- ozf/in^2
- oz/sq in
- ozf/sq in

## Conversion Tables

Select a look up table for converting a pressure reading in ounces force per square inch to other measurement units.

- psi » 0.1 to 2000 oz/in² → 0.0625 to 125.000 psi

**Low pressure measurement products**

- Trichloroethylene compatible 100 mbar Ex pressure transmitter
- 0-50 mbarg 4-20 mA output natural gas monitoring pressure sensor
- Natural gas booster pump inlet/outlet pressure transmitters for backup power generators
- TM Silicon Strain Gauge Pressure Transducer

## Measurement Unit Related Terms

More pages related to measurement unit technical terms.

- at – Technical Atmosphere Pressure Unit
- atm – Standard Atmosphere Pressure Unit
- bar Pressure Unit
- cmH2O – Centimetres of Water Column at 4 deg C Pressure Unit
- cmHg – Centimetres of Mercury at 0 deg C Pressure Unit
- daPa – Dekapascal Pressure Unit
- dyn/cm² – Dyne per Square Centimetre Pressure Unit
- ftH2O – Feet of Water Column at 4 deg C Pressure Unit
- g – Acceleration due to Gravity
- g/cm² – Grams per Square Centimetre Pressure Unit
- hPa – Hectopascal Pressure Unit
- inH2O – Inches of Water Column at 4 deg C Pressure Unit
- inHg – Inches of Mercury at 0 degrees C Pressure Unit
- kg/cm² – Kilogram per Square Centimetre Pressure Unit
- kg/mm² – Kilogram per Square Millimetre Pressure Unit
- kPa – Kilopascal Pressure Unit
- ksi – Kilopounds per Square Inch Pressure Unit
- mbar – Millibar Pressure Unit
- mH2O – Metres of Water Gauge at 4 deg C Pressure Unit
- mmH2O – Millimetres of Water Column at 4 deg C Pressure Unit
- mmHg – Millimetres of Mercury at 0 deg C Pressure Unit
- MPa – Megapascal Pressure Unit
- mPa – Millipascal Pressure Unit
- mTorr – Millitorr Pressure Unit
- N/cm² – Newton per Square Centimetre Pressure Unit
- N/m2 – Newton per Square Metre Pressure Unit
- N/mm² – Newton per Square Millimetre Pressure Unit
- Pa – Pascal Pressure Unit
- Pressure
- Pressure Units
- psf – Pounds per Square Foot Pressure Unit
- psi – Pounds per Square Inch Pressure Unit
- Specific Gravity
- Torr Pressure Unit
- tsf – Tons per Square Foot (USA, Short) Pressure Unit
- tsi – Tons per Square Inch (UK, Long) Pressure Unit
- tsi – Tons per Square Inch (USA, Short) Pressure Unit
- Water Density
- µHg – Micron of Mercury at 0 deg C Pressure Unit