Femtopascal is 1e-15 pascal units.
Femtopascals to PSI Converter — fPa to psi
Convert Femtopascal (fPa) to PSI (psi) using the exact conversion factor (1 femtopascal = 1.450377e-19 psi). See the formula, worked examples, conversion table, history, and common uses.
Femtopascals to PSI converter
Converter
Engineering Converter
Convert common stress, force, torque, power, and energy units used in engineering.
Context values
Some unit families need one extra value for a physically accurate result.
Pounds per square inch.
Result = input x 1e-15 / 6894.757293.
Stress Pressure units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Femtopascals to PSI
Femtopascal and PSI both measure a quantity used in structural or mechanical engineering — commonly stress, pressure, force, torque, power, or energy — where converting between the unit conventions used in different regions, industries, or equipment specifications is a routine part of design work. Specifically: Femtopascal is 1e-15 pascal units, and pounds per square inch.
Formula
psi = femtopascals × 1.450377e-19
This factor comes from each unit's defined relationship to the category's base unit: 1 femtopascal equals 1e-15 base units, and 1 psi equals 6894.75729317 base units, so dividing one by the other gives the direct femtopascal-to-psi factor of 1.450377e-19.
Simple example
1 fPa × 1.450377e-19 = 1.450377e-19 psi
1 femtopascal = 1.450377e-19 psi.
Real-world example
100 fPa × 1.450377e-19 = 1.450377e-17 psi
100 femtopascals = 1.450377e-17 psi.
Conversion table
| Femtopascal (fPa) | PSI (psi) |
|---|---|
| 1 fPa | 1.450377e-19 psi |
| 10 fPa | 1.450377e-18 psi |
| 50 fPa | 7.251887e-18 psi |
| 100 fPa | 1.450377e-17 psi |
| 500 fPa | 7.251887e-17 psi |
| 1,000 fPa | 1.450377e-16 psi |
Reverse conversion: PSI to Femtopascal
1.450377e-19 psi × 6.894757e+18 = 0.9999997399 fPa
1.450377e-19 psi = 0.9999997399 femtopascals.
femtopascals = psi × 6.894757e+18
For a page dedicated to this direction, see PSI to Femtopascal.
Understanding the Femtopascal (fPa)
Femtopascal is 1e-15 pascal units.
Understanding the PSI
PSI (psi) measures pressure. PSI (pounds-force per square inch) equals exactly 6,894.757293168 pascals. It is classified as a US/imperial customary unit.
Where it's used: United States (standard pressure unit for tires, tools, and plumbing)
Uses of the PSI today
- Tire pressure specifications in the US
- Hydraulic and pneumatic system ratings
- Plumbing, compressed-air tools, and industrial equipment ratings
History of the PSI
PSI is a derived unit from the pound-force and the inch, both themselves standardized through English and later international agreements rather than invented as a pressure unit from scratch.
It became the default pressure unit in US engineering as pound-force and inch-based measurement dominated American industry through the 19th and 20th centuries, and it remains in everyday use for tires and tools even as most other measurements in the US context stay imperial.
Historical origin. PSI was not the invention of a single named person; it developed through the process described above.
PSI — sources
- NIST Special Publication 811 — Guide for the Use of the International System of Units — Documents conversion factors for psi and other US customary pressure units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many psi are in 1 femtopascal?
1 femtopascal equals 1.450377e-19 psi, using the exact defined conversion factor rather than an estimate.
How do I convert femtopascal to psi?
Multiply the femtopascal value by 1.450377e-19. The converter above does this instantly to whatever precision you set.
How do I convert psi back to femtopascal?
Use the reverse factor: 1 psi equals 6.894757e+18 femtopascals. You can also use the swap control in the converter above to flip the direction instantly.
What is a femtopascal?
Femtopascal (fPa) is a unit of engineering.
What is a psi?
PSI (psi) measures pressure. PSI (pounds-force per square inch) equals exactly 6,894.757293168 pascals. It is classified as a US/imperial customary unit.
Is the femtopascal to psi conversion exact?
Yes. PSI (pounds-force per square inch) equals exactly 6,894.757293168 pascals. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
Why do engineering unit conventions vary so much by region and industry?
Pressure, force, and stress can be expressed in metric (pascal, newton), US customary (psi, pound-force), or older and industry-specific units (atmosphere, torr, kip) depending on the country, industry, and even the equipment manufacturer, which is why engineers routinely need to convert between them when working across specs from different sources.