Pressure Converter

Tire gauges read PSI, weather reports quote inches of mercury, and scuba tanks are filled in bar, so this converter moves a single reading between eight pressure units.

What is the Pressure Converter?

The Pressure Converter works through pascals as its common denominator, converting your entry in and then back out to the unit you pick. It offers Pascal, Bar, PSI, Atmosphere, mmHg (Torr), Kilopascal, Megapascal and inch of mercury. The factors are the standard ones: one bar is 100,000 pascals, one PSI is 6894.76, and one atmosphere is exactly 101,325.

Key Features

• Eight units from pascals up to megapascals, plus PSI and inHg
• Atmosphere fixed at the standard 101,325 pascals
• Results shown to ten decimal places for very small pressures
• Quick Conversions grid prints your value in all eight units
• Formula line restates the conversion in compact symbol form

Common Use Cases

• Setting tire pressure from a European door placard that lists bar, not PSI
• Converting a scuba cylinder's 3000 PSI fill into the bar your dive computer shows
• Reading an aviation altimeter setting in inHg against a metric station pressure report
• Checking a hydraulic component's megapascal rating against a PSI-rated hose

How to Use the Pressure Converter

1. Put the pressure reading into the Value box, decimals included.
2. Select the unit it came in from the From dropdown, which starts on Pascal.
3. Select what you need in the To dropdown, or hit the swap button to invert the pair.
4. Read the headline number, the unit name, and the formula line summarizing both sides.
5. Use the Quick Conversions grid when you want every unit at once rather than one target.

Tips for Best Results

• Check tire pressure cold, before driving; a warm tire can read several PSI above its true setting.
• One bar is exactly 100 kPa, so a placard reading 2.4 bar is simply 240 kPa.
• Tire and scuba gauges show gauge pressure, meaning pressure above the surrounding air rather than absolute.
• Millibars and hectopascals are not offered, but 1 hPa is 100 Pa if you need weather figures.

Why Use WiserWork's Pressure Converter?

Pressure wears more costumes than almost any other quantity: a tire at 32 PSI is also 2.21 bar, 220.6 kPa and about 2.18 atmospheres, and which number gets printed depends entirely on who printed the placard. Holding eight units in one place removes the guesswork about which is which. The math runs in your browser, so the reading you enter is never sent anywhere.

Who Uses the Pressure Converter?

Drivers and mechanics reconciling PSI placards with bar-marked gauges are the most frequent visitors. Divers converting cylinder fills, weather watchers translating inHg into metric readings, and engineers checking megapascal ratings on hydraulic and pneumatic parts all draw on the same eight units.

Frequently Asked Questions

How many PSI is one bar?

About 14.504 PSI. One bar is defined as 100,000 pascals and one PSI as 6894.76 pascals here, so the ratio falls straight out of those two factors.

Why is tire pressure supposed to be measured cold?

Driving heats the air inside the tire, and warmer air pushes harder on the walls. A tire checked after a highway run can read several PSI high, tempting you to release air you actually needed.

What does kPa mean on a tire placard?

Kilopascals, the metric unit many manufacturers print alongside PSI. Since one bar is 100 kPa, a placard reading 220 kPa is 2.2 bar, or roughly 32 PSI.

Does this convert gauge pressure or absolute pressure?

It converts the magnitude you type without assuming a reference point. Tire and scuba gauges read gauge pressure, so their numbers already exclude the roughly 14.7 PSI of surrounding atmosphere.

How much is one atmosphere?

Exactly 101,325 pascals, which works out to 1.01325 bar, about 14.696 PSI, and very close to 760 mmHg.

Are mmHg and Torr the same thing?

They are treated as a single option here, at 133.322 pascals. Strictly the two differ by less than one part in seven million, which never matters in practice.

Why is inHg used in weather and aviation?

US altimeter settings and barometric reports are traditionally given in inches of mercury. A standard sea-level reading of 29.92 inHg comes to about 101,320 pascals using the tool's 3386.39 factor.

Can I convert a scuba tank fill from PSI to bar?

Yes. A 3000 PSI fill converts to roughly 206.8 bar, which is why the 200 bar and 232 bar markings on European cylinders look unfamiliar to divers raised on PSI.

Why does the result show so many decimal places?

The main result keeps ten decimals so that tiny pressures expressed in pascals do not collapse to zero. The Quick Conversions cards use six.

Is megapascal useful outside engineering?

Rarely. MPa turns up on hydraulic components, pressure washers and material strength specs. One megapascal is about 145 PSI.

One pressure, eight names, and a placard that assumes you already know which one it means. Converting the reading before you touch the valve is the difference between a correctly inflated tire and a guess.