Enter the pressure range (e.g., psi), the voltage reading (volts), the upper voltage limit (volts), and the voltage lower limit (volts) into the calculator to determine the Pressure From Voltage. 

Voltage to Pressure Calculator

Voltage to Pressure
Pressure to Voltage

Convert a sensor voltage reading into pressure.

Pressure From Voltage Formula

The following formula is used to calculate the Pressure From Voltage.

P = PR * (Vr - VL) / (Vu - VL)
  • Where P is the pressure (same units as PR; commonly psi)
  • PR is the pressure range (full-scale span; commonly psi) 
  • Vr is the voltage reading (volts) 
  • VL is the voltage lower limit (volts) 
  • Vu is the voltage upper limit (volts)

Note: This form assumes a linear sensor where pressure is 0 at VL, and pressure is PR at Vu. If your sensor is calibrated from a nonzero lower pressure PL to an upper pressure PH, use:

P = P_L + (P_H - P_L) * (Vr - VL) / (Vu - VL)
Voltage to Pressure Conversion Table (1–5 V span; 0–100 psi full-scale)
Voltage (V) Pressure (psi) bar kPa atm
1.000.0000.0000.000
1.250.34534.4740.340
1.4100.68968.9480.680
1.6151.034103.4211.021
1.8201.379137.8951.361
2.0251.724172.3691.701
2.2302.068206.8432.041
2.4352.413241.3172.382
2.6402.758275.7902.722
2.8453.103310.2643.062
3.0503.447344.7383.402
3.2553.792379.2123.743
3.4604.137413.6864.083
3.6654.482448.1594.423
3.8704.826482.6334.763
4.0755.171517.1075.103
4.2805.516551.5815.444
4.4855.861586.0555.784
4.6906.205620.5286.124
4.8956.550655.0026.464
* Rounded to 3 decimals. Assumes linear sensor with V_low = 1.0 V, V_high = 5.0 V and pressure range 0–100 psi. Conversion factors: 1 psi = 0.0689476 bar = 6.89476 kPa = 0.068046 atm.

How to Calculate Pressure From Voltage?

The following example problems outline how to calculate the Pressure From Voltage.

Example Problem #1

  1. First, determine the pressure range (psi). In this example, the pressure range (psi) is given as 100.
  2. Next, determine the voltage reading (volts). For this problem, the voltage reading (volts) is given as 22.5.
  3. Next, determine the voltage lower limit (volts). In this case, the voltage lower limit (volts) is found to be 15.
  4. Next, determine the upper voltage limit. For this problem, this is 30.
  5. Finally, calculate the Pressure From Voltage using the formula above: 

P = PR * (Vr - VL) / (Vu - VL)

Inserting the values from above and solving yields: 

P = 100 * (22.5 - 15) / (30 - 15) = 50.00 (psi)


Example Problem #2

Using the same method as above, determine the variables required by the equation. For this example problem, these are provided as:

pressure range (psi) = 500

voltage reading (volts) = 3

voltage lower limit (volts) = 1

voltage upper limit (volts) = 5

Entering these given values yields: 

P = 500 * (3 - 1) / (5 - 1) = 250 (psi)