PSI to mmH2O Converter
Pressure · unit-converter
Convert PSI to mmH2O with a fixed input and output unit, step-by-step formula line, and reference tables. All calculations bridge through pascal with fixed definitions (standard atmosphere = 101,325 Pa; torr and mmHg = atm/760; plus industrial/manometer units like kgf/cm², inHg, inH2O, and mmH2O).
About PSI
Pounds-force per square inch (PSI) is common for tires, hydraulics, and US industrial equipment.
About mmH2O
Millimeters of water column (mmH2O) is used for very low differential pressure in instrumentation and ventilation.
How to convert psi to millimeter of water (mmh2o, 4 °c)
1 psi equals 703.0695796391225 mmh2o in this tool (via pascal):
1 psi = (6894.757293168 Pa ÷ 9.80665 Pa) mmh2o = 703.0695796391225 mmh2o
Each psi carries 6894.757293168 Pa and each mmh2o 9.80665 Pa, so one psi equals 6894.757293168 ÷ 9.80665 mmh2o.
Let p(psi) be pressure in PSI (psi), and p(mmh2o) in mmH2O (mmh2o). Then:
p(mmh2o) = p(psi) × (6894.757293168 / 9.80665)
Equivalently, divide by how many psi fit into one mmh2o (Pa per mmh2o divided by Pa per psi):
p(mmh2o) = p(psi) ÷ 0.0014223343307120308
Examples
Example #1: Convert 1 psi to mmh2o
1 psi = 1 psi × (6894.757293168/9.80665) mmh2o = 703.069579639 mmh2o
1 psi = 1 psi ÷ 0.0014223343307120308 = 703.069579639 mmh2o
1 psi × (6,894.757293168/9.80665) = 703.069580 mmh2o
Example #2: Convert 10 psi to mmh2o
10 psi = 10 psi × (6894.757293168/9.80665) mmh2o = 7030.69579639 mmh2o
10 psi = 10 psi ÷ 0.0014223343307120308 = 7030.69579639 mmh2o
10 psi × (6,894.757293168/9.80665) = 7,030.695796 mmh2o
Summary
To convert PSI to mmH2O, multiply the value in psi by (6894.757293168 Pa per psi) / (9.80665 Pa per mmh2o). Equivalently: value_mmh2o = value_psi × (6894.757293168 / 9.80665). Numerically, 1 psi equals 703.0695796391225 mmh2o.
Relationship context
Both PSI and mmH2O are converted by fixed multiples of the pascal. Multiplying by (Pa per psi) ÷ (Pa per mmh2o) gives the same result as passing through pascal, keeping bar, atm, PSI, kPa, hPa, torr, and mmHg consistent on the hub.
Conversion tables
| PSI (psi) | mmH2O (mmh2o) |
|---|---|
| 0.1 | 70.3069579639 |
| 1 | 703.069579639 |
| 2 | 1,406.13915928 |
| 3 | 2,109.20873892 |
| 4 | 2,812.27831856 |
| 5 | 3,515.3478982 |
| 6 | 4,218.41747783 |
| 7 | 4,921.48705747 |
| 8 | 5,624.55663711 |
| 9 | 6,327.62621675 |
| PSI (psi) | mmH2O (mmh2o) |
|---|---|
| 10 | 7,030.69579639 |
| 20 | 14,061.3915928 |
| 30 | 21,092.0873892 |
| 40 | 28,122.7831856 |
| 50 | 35,153.478982 |
| 60 | 42,184.1747783 |
| 70 | 49,214.8705747 |
| 80 | 56,245.5663711 |
| 90 | 63,276.2621675 |
| 100 | 70,306.9579639 |