Standard atmospheres to Pounds-force per square inch Calculator

Direct answer

Multiply the entered standard atmospheres value by 14.6959487758723 to express it in pounds-force per square inch (psi). This converts standard atmosphere (atm) to pound-force per square inch (psi) within the documented pressure family.

Variables and formula

• Standard atmospheres (atm): the source value measured in standard atmosphere.
• Pounds-force per square inch (psi): the same quantity expressed in pound-force per square inch.
• Conversion factor: 14.6959487758723 pounds-force per square inch per standard atmosphere.

Pounds-force per square inch = Standard atmospheres × 14.6959487758723

The generator emits numeric factors with at most 15 significant digits. Calculator results keep up to 10 significant digits for display; this formatting does not increase the precision of the measurement.

Unit definitions and named variants

Source unit: standard atmosphere (atm). The standard atmosphere is defined as exactly 101,325 Pa. Named variant used: Standard atmosphere (atm); not technical atmosphere (at) or a measured local atmospheric pressure. Reference: National Institute of Standards and Technology: NIST Guide to the SI, Appendix B.8: Factors for Units Listed Alphabetically.

Target unit: pound-force per square inch (psi). Psi in this family is pound-force per square international inch (lbf/in²). With standard gravity it is approximately 6894.75729316836 Pa. Named variant used: Pound-force per square inch using standard gravity; not pound-mass per square inch. Gauge versus absolute reference must be specified separately. Reference: National Institute of Standards and Technology: NIST Guide to the SI, Appendix B.8: Factors for Units Listed Alphabetically; National Institute of Standards and Technology: NIST Handbook 44 (2026), Appendix C: General Tables of Units of Measurement.

The atm-to-psi direction remains inside the pressure quantity; it changes the unit label and numerical scale, not the kind of quantity being measured.

Relationship and precision

This route uses at least one deliberately preserved rounded factor. Treat the displayed factor as an approximation at the precision documented below.

• atm relationship: The relationship to the pascal is exact.
• psi relationship: The preserved baseFactor 6894.757293 Pa is rounded from about 6894.75729316836 Pa, a difference of about 1.68×10⁻⁷ Pa per psi.

To audit the factor through the family base unit, divide the raw dataset factors 101325 by 6894.757293. The generator emits that quotient once at 15 significant digits as the canonical direct factor 14.6959487758723; runtime calculations do not divide the already-emitted base factors again.

Reproducible example

For 10 standard atmospheres, 10 × 14.6959487758723 = 146.959487758723 pounds-force per square inch. Repeating the same multiplication with the stated factor reproduces the displayed conversion before interface rounding.

Directional scale check

Because one standard atmosphere contains 14.6959487758723 pounds-force per square inch, the target number is larger than the source number for every positive input. Zero maps to zero, while negative inputs are rejected because this family models non-negative magnitudes.

Interpretation

Read the result as pounds-force per square inch, not standard atmospheres. A value entered as atm leaves the calculator labelled psi; this directional distinction matters even when the two units describe the same pressure quantity.

Assumptions and limitations

• Only non-negative pressure magnitudes are accepted; negative gauge readings require a signed, reference-aware model.
• This family converts non-negative pressure magnitudes only. It does not add or subtract atmospheric reference pressure when changing between absolute, gauge, differential, or vacuum readings.
• Input and output must refer to the same pressure reference and measurement conditions; a unit conversion alone cannot change the reference datum.

Common mistakes

• A standard atmosphere is a defined reference value, not today’s local air pressure.
• psig and psia share the same unit size but use different zero references; conversion between them requires ambient/reference pressure.

Continue within the Pressure family

See the Pressure conversion hub for its five-unit reference table and all 20 directed routes.

• Reverse the direction: Pounds-force per square inch to Standard atmospheres
• Compare another pressure route: Standard atmospheres to Pascals
• Compare another pressure route: Standard atmospheres to Kilopascals
• Compare another pressure route: Standard atmospheres to Bar
• Compare another pressure route: Pounds-force per square inch to Pascals

Assumptions

• The entered value uses standard atmospheres exactly as labelled.
• Only non-negative pressure magnitudes are accepted; negative gauge readings require a signed, reference-aware model.
• Rounding and measurement uncertainty remain the user's responsibility.

Sources and methodology

CalcMotive publishes the formula and assumptions so you can decide whether the estimate fits your use case. See our methodology standards.

• NIST Guide to the SI, Appendix B.8: Factors for Units Listed Alphabetically; National Institute of Standards and Technology; accessed Aug 7, 2026
• NIST Handbook 44 (2026), Appendix C: General Tables of Units of Measurement; National Institute of Standards and Technology; accessed Aug 7, 2026