Convert standard atmosphere to pound-force per square inch.

Convert standard atmosphere (atm) to pound-force per square inch (psi). This is a fixed-ratio conversion — multiply the input by the factor below.

Formula

psi = atm × 14.6959

Reference values

Things to watch for

• psi can be gauge (psig, above atmospheric) or absolute (psia). At sea level, psia = psig + 14.7. Specify which.
• 1 atm = 14.696 psi = 1.01325 bar = 101.325 kPa = 760 mmHg. These are all defined exactly.
• For tire pressure use psi or bar; for weather mbar/hPa; for vacuum work torr or Pa; for industrial fluid power MPa.

What is a standard atmosphere?

One standard atmosphere equals exactly 101,325 pascals — the average atmospheric pressure at sea level. Diving (depth = atm + 1 per 10 m of water), chemistry, and atmospheric reference.

What is a pounds per square inch?

One psi equals about 6,894.76 pascals — the pressure of one pound-force applied over one square inch. US tire pressure (typically 30-35 psi for cars), hydraulics, and engineering specifications.

What does atm look like in everyday objects?

If the unit feels abstract, comparing it to known objects often helps.

• 1 atm — standard atmospheric pressure at sea level.
• 2 atm — the pressure at 10 meters underwater.
• 100 atm — about the pressure 1 km deep in the ocean.

How to convert standard atmosphere to pounds per square inch

To convert a value from standard atmosphere (atm) to pounds per square inch (psi), apply the conversion factor shown in the formula above. The calculation is the same whether you do it by hand, in a spreadsheet, or with the live converter on this page.

Steps:

1. Take your input value in atm.
2. Apply the formula psi = atm × 14.6959.
3. The result is your value in psi.

For repeated calculations, save the formula in a spreadsheet or use the live converter at the top of this page — it handles the math automatically and displays the result as you type.

Frequently asked questions

How do I convert atm to psi?

Apply the formula atm → psi shown above, or just type your value into the converter at the top of this page. The result updates instantly.

Which is bigger, atm or psi?

This depends on the conversion ratio in the formula. If the factor multiplied by your value gives a larger number, then psi is the smaller unit (so it takes more of them to express the same quantity). If the result is smaller, then psi is the larger unit.

When would I use atm versus psi?

Both units measure pressure, so the choice depends on context. Standard atmosphere is typically used for tires, weather, hydraulics, and material strength; pounds per square inch similarly. Most professional fields standardize on one or the other based on regional conventions or technical tradition.

How precise is this atm to psi conversion?

The conversion factor shown is the internationally defined exact value (or the best-published approximation if the relationship is irrational, like degrees-to-radians). The live converter on this page uses double-precision floating-point math, accurate to about 15 significant digits — far beyond any practical engineering need.

Is the conversion ratio exact, or an approximation?

Most unit conversions between SI metric units, and between SI and US customary units, have been formally defined as exact values since the 1959 international yard-pound agreement and subsequent SI redefinitions. Exceptions are unit pairs that involve irrational numbers (radians, e.g.) or empirical conversions (like food calories, which depend on temperature). When in doubt, consult the formula at the top of this page.

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See also