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Pressure Unit Conversions — Bar, PSI, kPa
Pressure unit conversions for UK plumbing, heating and gas installations. Bar, psi, kPa, mbar, metres head and mmHg with common reference values.
Pressure Conversion Table
| Unit | bar | psi | kPa | mbar | m head |
|---|---|---|---|---|---|
| 1 bar | 1 | 14.504 | 100 | 1,000 | 10.2 |
| 1 psi | 0.06895 | 1 | 6.895 | 68.95 | 0.703 |
| 1 kPa | 0.01 | 0.1450 | 1 | 10 | 0.102 |
| 1 mbar | 0.001 | 0.01450 | 0.1 | 1 | 0.0102 |
| 1 m head | 0.0981 | 1.422 | 9.81 | 98.1 | 1 |
Common UK Pressure Reference Values
| Application | Typical Pressure | In bar | In psi |
|---|---|---|---|
| Mains water (min at stop tap) | 10m head | 1.0 | 14.5 |
| Mains water (typical) | 20-40m head | 2-4 | 29-58 |
| Combi boiler DHW | — | 1-3 | 14.5-43.5 |
| Sealed heating system | — | 1.0-1.5 (cold) | 14.5-21.8 |
| Sealed system PRV setting | — | 3.0 | 43.5 |
| Natural gas (domestic) | 21 mbar | 0.021 | 0.30 |
| LPG (regulated) | 37 mbar (propane) | 0.037 | 0.54 |
| Gas soundness test | 30 mbar | 0.030 | 0.44 |
| Tyre pressure (car) | — | 2.0-2.5 | 29-36 |
| Atmospheric pressure | 760 mmHg | 1.013 | 14.70 |
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Last updated: April 2026
Verified against UK standards · estimates only, confirm with your supplier.