OUSHKE professional hand tools and workshop tools
AIR PRESSURE CONVERTER

Bar to PSI Air Pressure Converter

Convert bar, psi, MPa and kgf/cm² exactly, in either direction. 1 bar = 14.5037738 psi, so 8 bar is 116 psi. The hard part starts at the gauge face — many gauges are not marked in bar.

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EXACT BOTH WAYS

How to Convert Bar to PSI and PSI to Bar

A fixed factor, an exact answer, and a shop shortcut you can trust for dialing a regulator.

1

The Factor Is
Fixed

It doesn’t change with temperature, altitude or the tool. It comes from the definitions of the two units.

2

The Exact
Values

1 bar = 14.5037738 psi. Going the other way, 1 psi = 0.0689476 bar. Both come from 1 psi = 6894.757 Pa and 1 bar = 100,000 Pa.

3

The Shop
Shortcut

Multiply bar by 14.5 to get psi, or divide psi by 14.5 to get bar. Close enough for most shop work, and worth knowing how close.

4

How Close the
Shortcut Is

At 6.2 bar the shortcut returns 89.9 psi against a true 89.92. At 12 bar, 174 against 174.05. The drift is about 0.03%, because 14.5 sits just below the real factor.

5

Why This Is
Different

No nearest size, no ladder to round against. Unlike a socket or wrench conversion, a pressure conversion has one correct answer.

BAR TO PSI CONVERTER

Convert Bar to PSI and PSI to Bar

Type either unit. Get the exact conversion, the workshop round, and the same pressure in MPa and kgf/cm². 1 bar = 14.5037738 psi.

Quick presets
Pressure in PSI
89.9 psi

Workshop round. Exact value: 89.9234 psi.

6.2 bar × 14.5037738 = 89.9234 psi
Bar 6.2 bar
PSI 89.9 psi
MPa 0.62 MPa
kgf/cm² 6.32 kgf/cm²
FACTOR REFERENCE

Fixed Conversion Factors

1 bar 14.5037738 psi
1 psi 0.0689476 bar
1 bar 0.1 MPa
1 kgf/cm² 0.980665 bar
SHOP AIR REFERENCE

The Bar to PSI Chart for Shop Air

EXACT FACTOR 1 bar = 14.5037738 psi

Shop air lives in a narrow band. Most pneumatic tools are rated near 90 psi, most systems run between 80 and 125 psi, and a single-stage compressor typically tops out around 8 bar. You need about five rows of this table, not fifty.

Rated Tool Pressure 90 psi ≈ 6.2 bar
Typical System Band 80–125 psi
Compressor Top 8 bar ≈ 116.0 psi
SI Equivalent 1 MPa = 10 bar
Bar PSI MPa kgf/cm²
0.5 7.3 0.05 0.51
1 14.5 0.10 1.02
2 29.0 0.20 2.04
3 43.5 0.30 3.06
4 58.0 0.40 4.08
5 72.5 0.50 5.10
6 87.0 0.60 6.12
6.2 89.9 Rated tool 0.62 6.32
6.3 91.4 kgf/cm² pairing 0.63 6.42
7 101.5 0.70 7.14
8 116.0 Compressor top 0.80 8.16
10 145.0 1.00 10.20
12 174.0 1.20 12.24
!

PSI values are rounded to one decimal. The MPa and kgf/cm² columns are included because those are the units many gauges actually carry. The rows at 6.2 and 6.3 bar are the two the next section explains.

UNIT DRIFT

Why 90 PSI Is Not 6.3 Bar

Most pneumatic tool manuals state a rated pressure of 90 psi / 6.3 bar. That pairing appears in manuals from Chicago Pneumatic, Hazet, Silverline, Ryobi and Universal Air Tools. It's close to universal. The arithmetic doesn't support it.

PUBLISHED PAIRING 90 psi / 6.3 bar
90 psi in bar 6.2053 bar
6.3 bar in psi 91.37 psi
Difference 1.37 psi
As percentage 1.53%
SAME LABEL · DIFFERENT UNIT
90 PSI Converts to 6.2 bar
VS
6.3 BAR Converts to 91.4 psi
1.53% gap between the manuals' pairing and the arithmetic — small, but larger than any rounding on this page
The number 6.3 is not invented. It's correct in a different unit.

A published ZIPP air tool conversion table lists 0.62 MPa, 6.2 bar, 90 psi and 6.3 kgf/cm² as the same pressure. 6.3 kgf/cm² converts to 89.61 psi, which is 90 psi. The likely origin is that the 6.3 travelled from the kgf/cm² column into the bar column and never came back.

01 If Your Gauge Reads bar

Set 6.2 for a tool rated at 90 psi.

02 If Your Gauge Reads kgf/cm²

Set 6.3. The number is right in that unit.

03 If Your Gauge Reads psi

Set 90. No conversion needed.

TWO BANDS · TWO TABLES

Tyre Pressures and Air Tool Reference Points

Tyre pressures sit far below shop air, and air tool ratings are working pressures rather than tank pressures. Both are worth keeping next to the main chart.

TYRE PRESSURES Bar · PSI
Bar PSI Typical Use
2.0 29.0 Small cars, light load
2.2 31.9 Common sedan setting
2.4 34.8 Mid-size cars and SUVs
2.6 37.7 Heavily loaded vehicles
2.9 42.1 Larger vehicles, towing
AIR SYSTEM Bar · PSI
Application Bar PSI
Rated tool pressure 6.2 90
Manual convention 6.3 91.4
Typical shop air 7 101.5
Compressor max 8 116.0
Two-stage high pressure 10–12 145–174
Min cut-out above cut-in 1 14.5
The rated pressure of an air tool is a working pressure, not a tank pressure. A compressor that cuts out at 8 bar and cuts back in at 6.5 bar doesn't deliver 8 bar at the tool. It delivers whatever survives the regulator, the filter, the couplings and the hose.
ERROR BUDGET

Five Places an Air Pressure Reading Goes Wrong

10,000:1 Spread between the smallest and largest error below

The conversion you came here to do is the smallest number in this table. Convert precisely, because it's the one term you control completely, and then spend your attention on the other four.

Rounding the conversion 0.005 psi
Reading kgf/cm² as bar 1.77 psi
Gauge class 2.5% of span 5 psi
Gauge read as absolute 14.70 psi
Pressure drop, tank to tool 15–50 psi
Δ
The arithmetic sits at the bottom of the list.

A ±4% wrench does not create a ±4% joint when the K-factor itself may be wrong by 20–25%. On air systems, the same principle applies: pressure drop is often ten times any error the arithmetic could introduce.

01 Measure with the Tool Running

Set the regulator with the tool flowing, not idle. Static pressure hides the loss.

02 Watch Two Gauges

If the regulator holds while the tool inlet falls, the loss is downstream in the hose or couplings.

03 Check the Accuracy Class

A class 2.5 gauge on a 0 to 200 psi scale may be 5 psi out anywhere on the dial.

WHAT THE DIAL SAYS

Gauges That Are Not Marked in Bar

This is the part a conversion can't fix on its own. Everything above assumes the number you're converting is in bar or psi. A large share of gauges show neither.

01
MPa Japanese and East Asian equipment
02
kgf/cm² Legacy machines and older nameplates
03
By Country of Origin Europe bar · US psi · Asia MPa or kgf
04
Dual-Scale Dials Removes the conversion step
!
Read the unit printed on the dial.

Read an MPa dial as bar and set 0.8, and you've set 0.8 bar instead of 8 bar — a factor-of-ten error, and the one unit mistake on this page large enough to damage equipment. kgf/cm² is the more dangerous of the two precisely because it's almost bar: 1 kgf/cm² is 0.980665 bar, a 2% difference that gets used interchangeably in the field. They aren't interchangeable.

Frequently Asked Questions (FAQs)

Find answers to common questions about our hand tools, their care, and usage. If you need additional information, our customer support team is ready to assist you.

Ask an expert
How many PSI is 1 bar?

One bar is 14.5037738 psi. Use 14.5 for setting a regulator by eye and the full factor for anything you write down.

90 psi is 6.2053 bar, which is 6.2 bar to one decimal. It isn't 6.3 bar.

Because 6.3 is the kgf/cm² equivalent of 90 psi, not the bar equivalent. 6.3 kgf/cm² works out to 89.61 psi, which rounds to 90. If your gauge reads bar rather than kgf/cm², set 6.2.

One kgf/cm² is 0.980665 bar, a difference of about 2%. The numbers are close enough to be used interchangeably by mistake and far enough apart to matter. At 90 psi, the gap is 1.77 psi.

Set it in whatever unit your gauge displays, and check which unit your tool's manual specifies in. If the two disagree, convert one to the other before you set anything. Then set the pressure with the tool running.

Almost always because of pressure drop rather than pressure. Measure at the tool inlet while the tool is running and compare that reading with the regulator gauge. If the pressure is correct and the tool is still weak, the next thing to check is air volume rather than pressure, and our air compressor CFM calculator covers that.