In short: 1 PSI equals about 0.0689 bar, 6.89 kPa, or 2.31 feet of water head. Enter any pressure reading above — in psi, bar, kPa, atmospheres, mmHg or water head — and the tool converts it to every other unit instantly.
These figures are planning aids based on standard reference values. For structural, regulatory or safety-critical work, confirm with a licensed engineer.
How to convert PSI to other pressure units
Every pressure unit measures the same physical quantity — force spread over an area — so converting between them is a single multiplication once you know the right factor. This calculator converts your reading to pascals internally, then back out to whichever unit you want to see.
Worked example. Convert 55 psi to bar: 55 × 0.0689476 = 3.792 bar. To find the equivalent water column height instead: 55 × 2.3067 = 126.9 ft. Both numbers describe the same pressure — they're just expressed in different units, the same way "1 mile" and "1.609 km" describe the same distance.
For a pressure that comes from an actual column of water rather than a gauge — say, the pressure at the bottom of a tank — the Static Pressure Calculator works the other direction, starting from height instead of a reading.
Gauge vs. absolute pressure
The atmosphere around you is already pushing on everything with about 14.7 psi at sea level. Most gauges — on a tire, a water meter, a pressure tank — are built to read zero at that ambient pressure, so they only show the pressure above atmospheric. That's gauge pressure, written psig.
Absolute pressure (psia) includes the atmosphere's own weight, so absolute always equals gauge plus atmospheric pressure at sea level: psia = psig + 14.6959. Scientific, HVAC and some pump-suction calculations need absolute pressure; everyday plumbing and tire readings are almost always gauge. Use the "Reading type" selector above to switch, and the result panel will show the equivalent in the other scale.
Local atmospheric pressure also drops with elevation, which is why the exact gauge-to-absolute offset shifts slightly at altitude — this tool uses the sea-level standard atmosphere (101,325 Pa) as the reference. For pressure that changes with depth in a tank or well, see the Water Pressure at Depth Calculator.
PSI conversion reference table
Common PSI values converted to bar, kPa, atmospheres, and feet/meters of water head. Every figure here matches what the calculator above returns for the same input.
| PSI | Bar | kPa | Atm | ft H₂O | m H₂O |
|---|---|---|---|---|---|
| 0 | 0 | 0 | 0 | 0 | 0 |
| 10 | 0.6895 | 68.95 | 0.6805 | 23.07 | 7.031 |
| 20 | 1.379 | 137.9 | 1.361 | 46.13 | 14.06 |
| 30 | 2.068 | 206.8 | 2.041 | 69.20 | 21.09 |
| 40 (min flow) | 2.758 | 275.8 | 2.722 | 92.27 | 28.12 |
| 50 | 3.447 | 344.7 | 3.402 | 115.3 | 35.15 |
| 60 (typical home) | 4.137 | 413.7 | 4.083 | 138.4 | 42.18 |
| 70 | 4.826 | 482.6 | 4.763 | 161.5 | 49.21 |
| 80 (IPC max) | 5.516 | 551.6 | 5.444 | 184.5 | 56.25 |
| 100 | 6.895 | 689.5 | 6.805 | 230.7 | 70.31 |
| 150 | 10.34 | 1034.2 | 10.21 | 346.0 | 105.5 |
| 200 | 13.79 | 1379.0 | 13.61 | 461.3 | 140.6 |
Worked examples
Checking a municipal supply
3.792 bar
A city meter reads 55 psi. An imported pressure regulator spec'd in bar needs 55 × 0.0689476 = 3.792 bar to match the setting correctly.
Tire pressure, US to metric
220.6 kPa
A tire placard calls for 32 psi. Converting for a metric-only gauge: 32 × 6.89476 = 220.6 kPa.
Sizing a gravity-feed tank
115.3 ft
To deliver 50 psi at a fixture using gravity alone, the tank needs roughly 50 × 2.3067 = 115.3 ft of elevation above it. See the Gravity Feed Pressure Calculator for a full layout.
What else affects the reading
Elevation and floor height. Every foot of elevation change shifts static water pressure by about 0.43 psi, which is why upper floors in a tall building read lower pressure than the ground floor — see the Water Pressure by Floor Calculator for that specific case.
Temperature. The 2.3067 ft-per-psi water-head shortcut assumes ordinary fresh water near room temperature. Hot water is slightly less dense, which shifts the factor by well under 1% — not enough to matter for household plumbing.
Gauge accuracy. Inexpensive mechanical gauges are typically accurate to only ±2–3% of full scale, so a reading of "60 psi" may really be anywhere from about 58 to 62 psi. For pump systems where the exact boost matters, the Booster Pump Pressure Calculator accounts for target pressure directly.
Frequently asked questions
How do I convert PSI to bar?
Multiply the PSI value by 0.0689476. For example, 55 psi × 0.0689476 = 3.792 bar. To go the other way, multiply bar by 14.5038 to get PSI.
How many PSI is one atmosphere?
One standard atmosphere equals 14.6959 psi (about 14.7 psi), 101,325 Pa, or 1.01325 bar. This is the sea-level reference used to convert between gauge and absolute pressure.
How do I convert PSI to feet of water head?
Multiply the PSI value by 2.3067. For example, 50 psi × 2.3067 = 115.3 ft of water. This shortcut assumes ordinary fresh water and is accurate to about 0.1% across normal indoor temperatures.
What is normal water pressure in a house, in PSI?
Most residential water pressure runs 40–80 psi. Codes such as the International Plumbing Code cap static pressure at 80 psi at the point of use; below about 40 psi, fixtures and appliances may not perform well.
Is PSI a gauge or absolute pressure reading?
It can be either — "psi" alone is ambiguous. "Psig" explicitly means gauge (relative to the surrounding atmosphere) and is what most water, tire and tank gauges show. "Psia" means absolute (measured from a perfect vacuum). This calculator defaults to gauge and lets you switch to absolute.
How many PSI is one bar?
One bar equals 14.5038 psi. Bar is common on European pressure gauges and equipment, so this conversion comes up often when matching imported parts to US-spec fittings.
Sources & references
- International Organization for Standardization. ISO 2533:1975, Standard Atmosphere.
- National Institute of Standards and Technology (NIST). Guide for the Use of the International System of Units (SI), NIST SP 811.
- Hydrostatic pressure relation, P = ρgh — standard fluid mechanics reference used across the pressure and head calculators on this site.
John Mac, PE
Water Systems Specialist · Austin, Texas
Texas-licensed Professional Engineer with 13+ years in residential water systems and 180+ completed projects. Writes and reviews the calculators on watercalculator.us. Read full bio
Texas PE (2016) · BS Civil Engineering, Hydraulics (2013)