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ksi to MPa Converter — Force Converter
Stress Converter
Structural
0

Formula
01

What this converter does

This converter turns ksi into megapascals and back instantly. It also handles psi, N/mm², kg/cm² and GPa — every pair uses an exact fixed factor. Type a value, pick your units, and read the result as you type.

A ksi is 1,000 psi = 6.8948 MPa. US steel is specified in ksi; SI codes use MPa. For force rather than stress, see the kip to kN converter.

02

The units it covers

Every unit here measures stress or pressure, converting through the megapascal with a fixed ratio.

View all units & their values
UnitSymbolValueMainly used
MegapascalMPa1SI stress (= N/mm²)
Newton per mm²N/mm²1Identical to MPa
Pound per in²psi0.006895US stress, small
Kilopound per in²ksi6.8948US structural stress
kgf per cm²kg/cm²0.09807Legacy metric stress
GigapascalGPa1000Elastic moduli
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The formula

Each unit has a fixed value in megapascals, so any conversion goes through the MPa once:

Conversion
result = value × factor_from ÷ factor_to

Where:

  • value = the number you typed, in the “from” unit
  • factor_from = the “from” unit’s value in megapascals
  • factor_to = the “to” unit’s value in megapascals
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Worked example

Convert 50 ksi to megapascals.

Step 1 · The factor
1 ksi = 6.8948 MPa
Step 2 · Multiply
50 × 6.8948 = 344.7 MPa

So 50 ksi is about 345 MPa — near Grade 50 / S355 steel.

05

The units in this example

Kilopound per in²symbol: ksi

A US stress unit of 1,000 psi, standard for steel yield and ultimate strength on imperial drawings.

Common stress conversions
  • 1 ksi = 1,000 psi
  • 1 ksi ≈ 6.895 MPa
  • 50 ksi ≈ 345 MPa
  • 1 ksi ≈ 70.31 kg/cm²
Megapascalsymbol: MPa

The SI stress unit, equal to one newton per square millimetre — used for material strength worldwide outside the US.

Common stress conversions
  • 1 MPa = 1 N/mm²
  • 1 MPa ≈ 145.0 psi
  • 1 MPa ≈ 0.145 ksi
  • 1 GPa = 1,000 MPa
06

FAQ

QHow many ksi is 1 MPa?
One MPa equals about 0.145 ksi. Divide the MPa figure by 6.8948.
QWhat is S355 steel in ksi?
S355 has 355 MPa yield, which is about 51.5 ksi.
08

Sources

ASTM International · NIST SP 811 — SI units

InfoCalculator Editorial Team Fact-checked
Updated Jul 2026 · 3 min read · Reviewed by the InfoCalculator editorial team