Engineering & process unit conversions — pressure, stress, flow, viscosity, torque and more. One value, every unit at once. No ads, no tracking.
ℹ️ Select a quantity, type a value, and read the result in every unit at once. All factors use exact SI definitions (e.g. 1 psi = 6894.757293168 Pa, 1 bar = 100 000 Pa). Temperature uses exact offset conversions. Pure client-side — nothing leaves your browser.
1 — Quantity
2 — Convert
Significant figures
All units
Basis
SI base and derived units — BIPM SI Brochure (9th ed.)
Imperial / US customary definitions — NIST Special Publication 811 (Guide for the Use of the SI)
1 in = 0.0254 m, 1 lb = 0.45359237 kg, 1 lbf = 4.4482216152605 N (exact, by definition)
1 psi = 6894.757293168 Pa · 1 bar = 100 000 Pa · 1 kg/cm² = 98 066.5 Pa · 1 atm = 101 325 Pa
📚 The most-used conversion factors in piping & process work, expressed to the SI base unit of each quantity. The converter uses these exact values.
Pressure & Stress (base: Pascal)
Unit
= Pascals (exact)
Note
bar
100 000
process & line pressure
psi
6894.757293168
lbf/in²
kg/cm²
98 066.5
"ata" / technical atmosphere
atm
101 325
standard atmosphere
MPa (N/mm²)
1 000 000
allowable stress, SMYS
ksi
6 894 757.293168
line-pipe grades
mmHg
133.322387415
vacuum / torr
mH₂O
9806.65
static head (4 °C)
Pressure and stress are dimensionally identical (force/area) but kept as separate quantities — line pressure is read in bar / psi / kg/cm², allowable stress in MPa / ksi.
Volume Flow (base: m³/s) & Temperature
Unit
= m³/s (exact)
Note
m³/h
1 / 3600
≈ 4.4029 US gpm per m³/h
US gpm
0.003785411784 / 60
US gallon = 3.785411784 L
cfm
0.028316846592 / 60
actual ft³/min
bbl/day
0.158987294928 / 86400
oil barrel basis
Temperature (offset): °F = °C × 9/5 + 32 · K = °C + 273.15 · °R = (°C + 273.15) × 9/5. Note: cfm / bbl-day here are volumetric (actual) flow — standard-condition gas rates (MMSCFD, Sm³/h) depend on reference P & T and are a separate calculation.
Force, Torque, Viscosity
Unit
= SI base (exact)
Quantity
kgf
9.80665 N
force
lbf
4.4482216152605 N
force
lbf·ft
1.3558179483314 N·m
torque
cP
0.001 Pa·s
dynamic viscosity
cSt
1×10⁻⁶ m²/s
kinematic viscosity
Report Details
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