What this converter does
This converter changes an elastic (Young’s) modulus from ksi to gigapascals and back. US codes quote steel as 29,000 ksi; metric codes as 200 GPa — the same stiffness in different units. Type a value and read the result instantly.
Modulus is a stress, so it uses the same exact pressure factors. Swap the arrow any time to convert the other way.
The units it covers
Elastic (Young’s) modulus is a stress, so it converts on the same fixed pressure factors.
View all units & their values
| Unit | Symbol | Value | Mainly used |
|---|---|---|---|
| Gigapascal | GPa | 1 | Steel ≈ 200, concrete ≈ 30 |
| Megapascal | MPa | 0.001 | Same unit as stress |
| Kilopound per square inch | ksi | 0.006895 | US design (steel E ≈ 29,000) |
| Newton per square millimetre | N/mm² | 0.001 | Identical to MPa |
| Megapound per square inch | Msi | 6.895 | US material data |
The formula
Each modulus unit has a fixed value in gigapascals, so the conversion is one multiplication:
result = value × factor_from ÷ factor_toWhere:
- value = the modulus you typed
- factor_from = its value in GPa
- factor_to = the target unit’s value in GPa
Worked example
Convert steel’s 29,000 ksi to GPa.
1 ksi = 0.00689476 GPa29,000 × 0.00689476 = 199.9 GPaSo 29,000 ksi ≈ 200 GPa — confirming the two figures describe the same steel.
The units in this example
The US customary modulus unit. Steel is 29,000 ksi; aluminium about 10,000 ksi in American practice.
- 1 ksi ≈ 0.006895 GPa
- 29,000 ksi ≈ 200 GPa
- 1 Msi = 1,000 ksi
- 1 ksi ≈ 6.895 MPa
The SI modulus unit. Steel is about 200 GPa, aluminium 69 GPa and concrete near 30 GPa.
- 1 GPa ≈ 145.0 ksi
- 200 GPa ≈ 29,008 ksi
- 1 GPa = 1,000 MPa
- 1 GPa = 1,000 N/mm²