# Psi vs. Bar: What's the Difference?

Edited by Aimie Carlson || By Janet White || Updated on October 4, 2023
Psi vs. Bar: "Psi" is a unit of pressure representing pounds per square inch, while "Bar" is a metric unit measuring atmospheric pressure.

## Key Differences

Psi and Bar are both units of measurement that convey pressure, but they originate from different measurement systems and have different values. The term "Psi" stands for pounds per square inch and is used predominantly in the imperial system, primarily in the United States. In contrast, "Bar" is employed in the metric system and is accepted globally.
When measuring tire pressure, hydraulic systems, or certain industrial equipment, especially in the United States, Psi is commonly used. Bar, on the other hand, is frequently utilized in scientific research, meteorological reports, and many other applications, especially outside of the U.S.
One key distinction is the magnitude of these units. One bar is substantially larger than one psi. Specifically, one bar is equivalent to approximately 14.5 psi. Therefore, a reading in Bar will often be a much smaller number than its Psi equivalent for the same pressure.
The choice between using Psi or Bar often depends on regional standards and the specific context of the measurement. For instance, while the U.S. may rely on Psi for many applications, European countries might lean more toward using Bar.
Both Psi and Bar serve essential roles in various fields, including engineering, science, and meteorology. They enable professionals and researchers to quantify and communicate pressure accurately, albeit through different units.

## Comparison Chart

Imperial.
Metric.

### Abbreviation

Psi (pounds per square inch).
Bar.

### Typical Usage

Used mainly in the U.S.
Used globally, especially outside of the U.S.

### Equivalent in the other unit

1 Psi is approximately 0.0689 Bar.
1 Bar is approximately 14.5 Psi.

### Fields of Application

Tire pressure, hydraulic systems, industrial equipment.
Meteorological reports, scientific research, general use.

## Psi and Bar Definitions

#### Psi

Commonly used in the United States for pressure measurements.
American car tires often display their recommended pressure in Psi.

#### Bar

A metric unit of atmospheric pressure.
The atmospheric pressure today is 1.01 Bar.

#### Psi

Used for measuring force per unit area.
The gas pressure in the cylinder is 2,000 Psi.

#### Bar

Used in scientific and meteorological contexts.
The research paper cited readings in Bar rather than Psi.

#### Psi

A unit of pressure in the Imperial system.
The tire pressure should be maintained at 32 Psi.

#### Bar

Represents force exerted on a surface area of one square meter.
Divers monitor pressure in Bar when considering depth and safety.

#### Psi

Represents pounds per square inch.
The hydraulic system operates at 1,500 Psi.

#### Bar

A relatively long, straight, rigid piece of solid material used as a fastener, support, barrier, or structural or mechanical member.

#### Psi

A standard for various industrial and mechanical applications.
The equipment's safety limit is 500 Psi.

#### Bar

A solid oblong block of a substance or combination of ingredients, such as soap or candy.

#### Psi

The 23rd letter of the Greek alphabet. See Table at alphabet.

#### Bar

A usually rectangular slice of any of various flat baked confections that are typically dense in texture.

#### Psi

Parapsychological phenomena or abilities considered as a group.

#### Bar

A rectangular block of a precious metal.

#### Psi

(countable) The twenty-third letter of Classical and Modern Greek and the twenty-fifth letter of Old and Ancient Greek.

#### Bar

See horizontal bar.

#### Psi

A form of psychic energy.

#### Bar

A horizontal rod that marks the height to be cleared in high jumping or pole vaulting.

#### Psi

A unit of pressure

#### Bar

A standard, expectation, or degree of requirement
A leader whose example set a high bar for others.

#### Psi

The 23rd letter of the Greek alphabet

#### Bar

Something that impedes or prevents action or progress
A poor education was a bar to his ambitions.

#### Bar

A ridge, as of sand or gravel, on a shore or streambed, that is formed by the action of tides or currents.

#### Bar

A narrow marking, as a stripe or band.

#### Bar

A narrow metal or embroidered strip worn on a military uniform indicating rank or service.

#### Bar

Chiefly British A small insignia worn on a military decoration indicating that it has been awarded an additional time.

#### Bar

(Heraldry) A pair of horizontal parallel lines drawn across a shield.

#### Bar

The nullification, defeat, or prevention of a claim or action.

#### Bar

The process by which nullification, defeat, or prevention is achieved.

#### Bar

The railing in a courtroom separating the participants in a legal proceeding from the spectators.

#### Bar

A court or courtroom.

#### Bar

Attorneys considered as a group. Used with the.

#### Bar

The profession of law. Used with the.

#### Bar

A vertical line drawn through a staff to mark off a measure.

A measure.

#### Bar

Variant of barre.

#### Bar

A counter at which drinks, especially alcoholic drinks, and sometimes food, are served.

#### Bar

An establishment or room having such a counter.

#### Bar

A unit of pressure equal to one million (106) dynes per square centimeter.

#### Bar

To fasten securely with a long, straight, rigid piece of material
Barred the gate.

#### Bar

To shut in or confine
Barred themselves in the basement.

#### Bar

To obstruct or impede; block
Barred the access route.

#### Bar

To keep out; exclude
Tourists are barred from this room.

#### Bar

To prohibit or prevent (someone) from doing something
Failing the eye exam barred him from driving.

#### Bar

To prohibit (an action)
The state bars the dumping of waste in the river.

#### Bar

(Law) To nullify, defeat, or prevent (a claim or action).

#### Bar

To rule out; except
Can we bar the possibility of foul play?.

#### Bar

To mark with stripes or bands.

#### Bar

Chiefly British Except for; excluding
This was your best performance, bar none.

#### Bar

A solid, more or less rigid object of metal or wood with a uniform cross-section smaller than its length.
The window was protected by steel bars.

#### Bar

A solid metal object with uniform (round, square, hexagonal, octagonal or rectangular) cross-section; in the US its smallest dimension is 4 inch or greater, a piece of thinner material being called a strip.
Ancient Sparta used iron bars instead of handy coins in more valuable alloy, to physically discourage the use of money.
We are expecting a carload of bar tomorrow.

#### Bar

A cuboid piece of any solid commodity.
Bar of chocolate
Bar of soap

#### Bar

A broad shaft, band, or stripe.
A bar of light
A bar of colour

#### Bar

A long, narrow drawn or printed rectangle, cuboid or cylinder, especially as used in a bar code or a bar chart.

#### Bar

(typography) Any of various lines used as punctuation or diacritics, such as the pipe ⟨{{!}}⟩, fraction bar (as in 12), and strikethrough (as in Ⱥ), formerly including oblique marks such as the slash.

#### Bar

(mathematics) The sign indicating that the characteristic of a logarithm is negative, conventionally placed above the digit(s) to show that it applies to the characteristic only and not to the mantissa.

#### Bar

(physics) A similar sign indicating that the charge on a particle is the negative of its usual value (and that consequently the particle is in fact an antiparticle).

#### Bar

A business selling alcoholic drinks for consumption on the premises, or the premises themselves; a public house.
The street was lined with all-night bars.

#### Bar

The counter of such premises.
Step up to the bar and order a drink.

#### Bar

A counter, or simply a cabinet, from which alcoholic drinks are served in a private house or a hotel room.

#### Bar

, juice bar, etc.}} Premises or a counter serving any type of beverage.

#### Bar

An establishment where alcohol and sometimes other refreshments are served.

#### Bar

An informal establishment selling food to be consumed on the premises.
A burger bar
A local fish bar

#### Bar

An establishment offering cosmetic services.
A nail bar; a brow bar

#### Bar

An official order or pronouncement that prohibits some activity.
The club has lifted its bar on women members.

#### Bar

Anything that obstructs, hinders, or prevents; an obstruction; a barrier.

#### Bar

A metasyntactic variable representing an unspecified entity, often the second in a series, following foo.
Suppose we have four objects, foo, bar, baz and quux.

#### Bar

A dividing line (physical or notional) in the chamber of a legislature beyond which only members and officials may pass.

#### Bar

The railing surrounding the part of a courtroom in which the judges, lawyers, defendants and witnesses stay.

#### Bar

The bar exam, the legal licensing exam.
He's studying hard to pass the Bar this time; he's failed it twice before.

#### Bar

Collectively, lawyers or the legal profession; specifically applied to barristers in some countries, but including all lawyers in others.
He was called to the bar, he became a barrister.

#### Bar

One of an array of bar-shaped symbols that display the level of something, such as wireless signal strength or battery life remaining.
I don't have any bars in the middle of this desert.

#### Bar

(music) A vertical line across a musical staff dividing written music into sections, typically of equal durational value.

#### Bar

(music) One of those musical sections.

#### Bar

(sports) A horizontal pole that must be crossed in the high jump and pole vault.

#### Bar

(metaphorical) Any level of achievement regarded as a challenge to be overcome.

The crossbar.

#### Bar

(backgammon) The central divider between the inner and outer table of a backgammon board, where stones are placed if they are hit.

#### Bar

An addition to a military medal, on account of a subsequent act.

#### Bar

A linear shoaling landform feature within a body of water.

#### Bar

A ridge or succession of ridges of sand or other substance, especially a formation extending across the mouth of a river or harbor or off a beach, and which may obstruct navigation. (FM 55-501).

#### Bar

(heraldry) One of the ordinaries in heraldry; a diminutive of a fess.

#### Bar

A city gate, in some British place names.

#### Bar

(mining) A drilling or tamping rod.

#### Bar

(mining) A vein or dike crossing a lode.

#### Bar

(architecture) A gatehouse of a castle or fortified town.

#### Bar

(farriery) The part of the crust of a horse's hoof which is bent inwards towards the frog at the heel on each side, and extends into the centre of the sole.

#### Bar

The space between the tusks and grinders in the upper jaw of a horse, in which the bit is placed.

#### Bar

(slang) A measure of drugs, typically one ounce.

#### Bar

A non-SI unit of pressure equal to 100,000 pascals, approximately equal to atmospheric pressure at sea level.

#### Bar

(transitive) To obstruct the passage of (someone or something).
Our way was barred by a huge rockfall.

#### Bar

(transitive) To prohibit.
I couldn't get into the nightclub because I had been barred.

#### Bar

(transitive) To lock or bolt with a bar.
Bar the door

#### Bar

To imprint or paint with bars, to stripe.

#### Bar

Except, other than, besides.
He invited everyone to his wedding bar his ex-wife.

#### Bar

(horse racing) Denotes the minimum odds offered on other horses not mentioned by name.
Leg At Each Corner is at 3/1, Lost My Shirt 5/1, and it's 10/1 bar.

#### Bar

A piece of wood, metal, or other material, long in proportion to its breadth or thickness, used as a lever and for various other purposes, but especially for a hindrance, obstruction, or fastening; as, the bars of a fence or gate; the bar of a door.
Thou shalt make bars of shittim wood.

#### Bar

An indefinite quantity of some substance, so shaped as to be long in proportion to its breadth and thickness; as, a bar of gold or of lead; a bar of soap.

#### Bar

Anything which obstructs, hinders, or prevents; an obstruction; a barrier.
Must I new bars to my own joy create?

#### Bar

A bank of sand, gravel, or other matter, esp. at the mouth of a river or harbor, obstructing navigation.

#### Bar

Any railing that divides a room, or office, or hall of assembly, in order to reserve a space for those having special privileges; as, the bar of the House of Commons.

#### Bar

The railing that incloses the place which counsel occupy in courts of justice. Hence, the phrase at the bar of the court signifies in open court.

#### Bar

Any tribunal; as, the bar of public opinion; the bar of God.

#### Bar

A barrier or counter, over which liquors and food are passed to customers; hence, the portion of the room behind the counter where liquors for sale are kept.

#### Bar

An ordinary, like a fess but narrower, occupying only one fifth part of the field.

#### Bar

A broad shaft, or band, or stripe; as, a bar of light; a bar of color.

#### Bar

A vertical line across the staff. Bars divide the staff into spaces which represent measures, and are themselves called measures.

#### Bar

The space between the tusks and grinders in the upper jaw of a horse, in which the bit is placed.

#### Bar

A drilling or tamping rod.

#### Bar

A gatehouse of a castle or fortified town.

#### Bar

To fasten with a bar; as, to bar a door or gate.

#### Bar

To restrict or confine, as if by a bar; to hinder; to obstruct; to prevent; to prohibit; as, to bar the entrance of evil; distance bars our intercourse; the statute bars my right; the right is barred by time; a release bars the plaintiff's recovery; - sometimes with up.
He barely looked the idea in the face, and hastened to bar it in its dungeon.

#### Bar

To except; to exclude by exception.
Nay, but I bar to-night: you shall not gauge meBy what we do to-night.

#### Bar

To cross with one or more stripes or lines.
For the sake of distinguishing the feet more clearly, I have barred them singly.

#### Bar

A room or establishment where alcoholic drinks are served over a counter;
He drowned his sorrows in whiskey at the bar

#### Bar

A counter where you can obtain food or drink;
He bought a hot dog and a coke at the bar

#### Bar

A rigid piece of metal or wood; usually used as a fastening or obstruction or weapon;
There were bars in the windows to prevent escape

#### Bar

Musical notation for a repeating pattern of musical beats;
The orchestra omitted the last twelve bars of the song

#### Bar

An obstruction (usually metal) placed at the top of a goal;
It was an excellent kick but the ball hit the bar

#### Bar

The act of preventing;
There was no bar against leaving
Money was allocated to study the cause and prevention of influenza

#### Bar

(meteorology) a unit of pressure equal to a million dynes per square centimeter;
Unfortunately some writers have used bar for one dyne per square centimeter

#### Bar

A submerged (or partly submerged) ridge in a river or along a shore;
The boat ran aground on a submerged bar in the river

#### Bar

The body of individuals qualified to practice law in a particular jurisdiction;
He was admitted to the bar in New Jersey

#### Bar

A block of solid substance (such as soap or wax);
A bar of chocolate

#### Bar

A portable .30 caliber magazine-fed automatic rifle operated by gas pressure; used by United States troops in World War I and in World War II and in the Korean War

#### Bar

A horizontal rod that serves as a support for gymnasts as they perform exercises

#### Bar

A heating element in an electric fire;
An electric fire with three bars

#### Bar

(law) a railing that encloses the part of the courtroom where the judges and lawyers sit and the case is tried;
Spectators were not allowed past the bar

#### Bar

Prevent from entering; keep out;
He was barred from membership in the club

#### Bar

Render unsuitable for passage;
Block the way

#### Bar

Expel, as if by official decree;
He was banished from his own country

#### Bar

Secure with, or as if with, bars;
He barred the door

#### Bar

Commonly used outside the U.S. for pressure measurements.
European tire pressures are often indicated in Bar.

#### Bar

A standard in many countries for measuring pressure.
The industrial machine operates at 10 Bar.

## FAQs

#### Is Bar used globally?

Yes, Bar is a metric unit and is used globally, especially outside of the U.S.

#### Which system does Psi belong to?

Psi belongs to the Imperial system of measurement.

#### Which unit is larger, Psi or Bar?

Bar is larger; 1 Bar is equivalent to approximately 14.5 Psi.

#### Are Psi and Bar both units of pressure?

Yes, both Psi and Bar are units that measure pressure.

#### Which unit might be found on a European car tire?

A European car tire will likely indicate pressure in Bar.

#### Is Bar solely a metric unit?

Yes, Bar is a metric unit of pressure.

#### In which country is Psi predominantly used?

Psi is predominantly used in the United States.

#### Are there other units of pressure besides Psi and Bar?

Yes, there are other units like pascal (Pa) and atmosphere (atm).

#### How is Psi abbreviated?

Psi is abbreviated as "Psi," which stands for pounds per square inch.

#### Which industries often use Psi?

Industries like automotive, hydraulics, and some manufacturing sectors in the U.S. frequently use Psi.

#### Can Psi and Bar be converted into each other?

Yes, they can be converted; for instance, 1 Bar is about 14.5 Psi.

#### Why is it essential to understand both Psi and Bar?

Understanding both Psi and Bar is crucial due to regional variations and the specific requirements of different applications.

#### Is there a standard conversion factor between Psi and Bar?

Yes, 1 Bar is approximately equivalent to 14.5 Psi.

#### Which unit might be used in deep-sea diving?

Bar is often used in deep-sea diving to measure pressure.

#### Which unit might be more common in scientific publications?

Bar is often more common in scientific publications, especially those with an international audience.

#### Is Bar used in weather reporting?

Yes, Bar is often used in meteorological reports to indicate atmospheric pressure.

#### In what context might one see Bar used?

Bar is used in scientific research, weather reporting, and general pressure measurements in many countries.

#### Does Psi have a symbol?

Psi is typically represented by the symbol "psi" or "Psi."

#### Are there tools to convert Psi to Bar and vice versa?

Yes, there are various online tools and conversion tables to convert between Psi and Bar.

#### Are readings in Psi typically larger in number than in Bar for the same pressure?

Yes, because Bar is a larger unit, readings in Psi will typically be larger in number for the same pressure.