terican

BIPM-ratified constants · v1.0

Converter

Pascal, to ksi converter calculator.

Convert pressure between pascals and ksi using the exact factor 6,894,757.2932. Supports Pa-to-ksi and ksi-to-Pa for engineering and materials applications.

From

pascal (pa)

pa_to_ksi

1000000 pa_to_ksi =0.145038Converted Pressure

Equivalents

Precision: 6 dp · Notation: Decimal · 2 units

→ KSI

Pascal (Pa)pa_to_ksi0.145038

Pa

KSI → Pascalksi_to_pa6.89e12

Common pairings

1 pa_to_ksiequals6,894,757 ksi_to_pa
1 ksi_to_paequals1.45e-7 pa_to_ksi

The conversion

How the value
is computed.

Pascal to Ksi Conversion: Formula, Derivation, and Engineering Applications

Converting between pascals (Pa) and kilopounds per square inch (ksi) is a routine requirement in structural engineering, geotechnical analysis, and materials science. The pascal is the SI unit of pressure, while ksi — equal to 1,000 pounds per square inch — dominates American engineering practice for specifying steel yield strengths, concrete compressive strengths, and soil bearing capacities. This calculator performs both Pa-to-ksi and ksi-to-Pa conversions using the metrologically exact conversion factor.

The Conversion Formula

The relationship between pascals and ksi is anchored to the exact factor documented in the NIST Guide for the Use of the International System of Units (SP 811):

ksi = Pa ÷ 6,894,757.2932

For the reverse direction:

Pa = ksi × 6,894,757.2932

Derivation of the Conversion Factor

The factor 6,894,757.2932 traces directly to the definition of one pound-force per square inch. Per NIST SP 811 and the NCEES FE Reference Handbook, one psi equals 6,894.757293168 Pa exactly. Because ksi represents exactly 1,000 psi, the full chain resolves as follows:

  • 1 psi = 6,894.757293168 Pa
  • 1 ksi = 1,000 psi = 6,894,757.2932 Pa
  • Therefore: ksi = Pa ÷ 6,894,757.2932

This factor is defined to machine precision and remains invariant across all conversion operations. The pound-force itself is defined in terms of the standard gravitational acceleration (9.80665 m/s²) and the avoirdupois pound (0.45359237 kg exactly), making this conversion path an exact mathematical relationship rather than an approximation.

Variable Definitions

  • Pa (Pascal): The SI derived unit of pressure equal to one newton per square meter (N/m²). Standard atmospheric pressure is 101,325 Pa.
  • ksi (Kilopounds per Square Inch): An imperial-US customary pressure unit equal to 1,000 psi or approximately 6.895 MPa. Predominant in ASTM material specifications, AISC steel design, and ACI concrete standards.
  • Conversion Factor: 6,894,757.2932 Pa per ksi — exact to the precision of the international pound-force definition.

Precision and Significant Figures

When performing conversions, engineers must consider appropriate rounding. The full factor 6,894,757.2932 should be retained in software and spreadsheets to ensure computational accuracy; however, reported results should respect significant figures in the input. If a measurement is reported as 250 MPa (3 significant figures), the converted result of 36.26 ksi should be similarly constrained. Retaining excessive decimal places implies false precision and can mislead code officials or material engineers reviewing specifications.

Worked Examples

Example 1: Concrete Compressive Strength

A normal-weight concrete mix is specified at 27,579,029 Pa compressive strength. Converting to ksi:

ksi = 27,579,029 ÷ 6,894,757.2932 = 4.00 ksi

This corresponds precisely to 4,000 psi — the standard design strength for general structural concrete under ACI 318.

Example 2: Structural Steel Yield Strength

ASTM A36 steel carries a minimum yield strength of 250 MPa (250,000,000 Pa). Converting to ksi:

ksi = 250,000,000 ÷ 6,894,757.2932 ≈ 36.26 ksi

This aligns with the A36 designation naming convention, which specifies a 36 ksi nominal yield — confirming the formula's accuracy against a widely recognized material standard.

Example 3: Soil Bearing Capacity

A geotechnical investigation reports an allowable bearing pressure of 383,000 Pa for a bridge foundation. Converting to ksi:

ksi = 383,000 ÷ 6,894,757.2932 ≈ 0.0555 ksi (55.5 psi)

Foundation engineers submitting AASHTO LRFD designs must express soil pressures in ksi; this conversion bridges SI lab outputs to US code formats.

Practical Applications by Discipline

  • Structural Engineering: AISC 360 and AASHTO LRFD specifications express all stresses, moduli, and strengths in ksi. FEA software reporting in Pa requires conversion before code-check entries.
  • Geotechnical Engineering: Laboratory consolidation and triaxial test results are often output in Pa or kPa by digital acquisition systems but must be reported in ksi for US bridge and retaining-wall design.
  • Materials Science and Testing: Universal testing machines calibrated in SI produce tensile and compressive results in Pa; ASTM certificates require ksi equivalents for US product acceptance.
  • Hydraulic and Mechanical Systems: High-pressure fluid systems specified internationally in MPa (Pa × 10⁶) must match ksi-rated component datasheets for North American procurement.

Quick-Reference Conversion Table

  • 1,000 Pa = 0.000145 ksi
  • 1 MPa (1,000,000 Pa) = 0.1450 ksi
  • 6,894,757 Pa ≈ 1.000 ksi
  • 100 MPa = 14.504 ksi
  • 200 MPa = 29.008 ksi (Grade 60 rebar minimum tensile strength: 414 MPa = 60.0 ksi)
  • 500 MPa = 72.52 ksi

Reference

Frequently asked questions

What is the exact formula to convert pascal to ksi?
To convert pascal to ksi, divide the pascal value by 6,894,757.2932. This factor derives from the NIST-defined equivalence of 1 psi = 6,894.757293168 Pa, scaled by 1,000 because ksi equals 1,000 psi. For example, 13,789,514.6 Pa equals exactly 2.000 ksi. The NCEES FE Reference Handbook uses this same factor for unit-conversion problems on the Fundamentals of Engineering exam.
How many pascals are in 1 ksi?
One ksi equals exactly 6,894,757.2932 pascals. This value comes from multiplying the exact psi-to-pascal factor (6,894.757293168 Pa per psi, per NIST SP 811) by 1,000, since ksi means kilo-pounds per square inch. In more familiar terms, 1 ksi is approximately 6.895 MPa or 68.95 bar — a magnitude common in structural steel and high-strength bolt specifications.
What is ksi and why do structural engineers prefer it over pascals?
Ksi stands for kilopounds per square inch (1,000 psi). American structural engineers prefer ksi because all major US design standards — AISC 360 for steel, ACI 318 for concrete, and AASHTO LRFD for bridges — express material strengths, stresses, and moduli in ksi. For example, ASTM A992 wide-flange steel is specified at Fy = 50 ksi (345 MPa). Working in ksi keeps calculations consistent with codebook tables and avoids large exponents that appear when using pascals for high-strength materials.
How do I convert ksi back to pascal?
To reverse-convert ksi to pascal, multiply the ksi value by 6,894,757.2932. For example, Grade 60 reinforcing steel has a yield strength of 60 ksi; multiplying by 6,894,757.2932 gives 413,685,438 Pa, or approximately 413.7 MPa, which matches the metric specification of 420 MPa (rounded per ASTM A615). This bidirectional capability is built into the calculator above using the same exact conversion factor in both directions.
What is the difference between psi and ksi when converting from pascal?
Psi (pounds per square inch) and ksi (kilopounds per square inch) differ by a factor of exactly 1,000. To convert pascals to psi, divide by 6,894.757293168. To convert pascals to ksi, divide by 6,894,757.2932 — which is the psi factor multiplied by 1,000. Numerically, 1 MPa equals 145.038 psi or 0.145038 ksi. Engineers use ksi instead of psi to keep numbers manageable: ASTM A36 steel at 36,000 psi is far easier to reference as 36 ksi in design tables and calculations.
What are typical pascal and ksi values for common engineering materials?
Common engineering reference values include: normal-strength concrete at 20.7–34.5 MPa (3–5 ksi); ASTM A36 structural steel yield at 250 MPa (36.3 ksi); high-strength A572 Grade 50 steel at 345 MPa (50 ksi); Grade 60 rebar at 414 MPa (60 ksi); and prestressing strand at 1,860 MPa (270 ksi). Soil allowable bearing pressures typically range from 100–500 kPa (0.0145–0.0725 ksi) for sands and gravels. These benchmarks make the pascal-to-ksi converter indispensable for cross-referencing international material datasheets with US code requirements.