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Engineering Units

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Engineering unit conversion

Enter values, then press Calculate.

How to use

  1. Under kind, choose pressure, force, or speed. Default is pressure.
  2. Enter a value and unit. Changing kind switches the unit list to that quantity.
  3. Press Convert, or change value, kind, or unit, to see the other units of the same kind.
  4. Pressure is based on Pa, force on N, speed on m/s.
  5. Reset returns to pressure and value 1. For certification and calibration use official conversion tables.

Key concepts

Engineering unit conversion moves between SI and imperial/US customary within one physical quantity. Pressure: Pa, kPa, MPa, bar, atm, psi, mmHg. 1 atm = 101325 Pa, 1 bar = 10^5 Pa, 1 psi ≈ 6894.76 Pa, 1 mmHg ≈ 133.322 Pa. Force: N, kN, kgf, lbf, dyn, with 1 kgf = 9.80665 N. Changing kind refills the unit select from scratch while keeping the value. Switching from pressure to speed also changes what the number means—re-enter the value. The table shows only the chosen kind; force and pressure are not mixed on one screen.

Speed: m/s, km/h, mph, knot, ft/s. 1 km/h = 1/3.6 m/s, 1 knot ≈ 0.514444 m/s. Length, weight, and power are not in this kind—use dedicated converters. Display is a reference decimal and may differ from legal metrology rounding. Tires and hydraulics often use psi and bar; labs use Pa and kPa. kgf is shop convention; N is SI. Knots match aviation and marine logs. Reference decimals can differ from a certificate’s significant figures.

Example

1 atm is 101325 Pa, 101.325 kPa, about 14.696 psi, and close to 760 mmHg. Force 9.80665 N is 1 kgf. Speed 100 km/h is about 27.778 m/s, 62.137 mph, 53.996 knot. To convert tire psi to kPa, pick pressure. 32 psi is about 220.6 kPa, 2.206 bar. 1000 N is about 101.97 kgf, 224.8 lbf. 10 m/s is 36 km/h, about 19.44 knot.

Related: Length converter · Power unit converter

Frequently asked questions

Do I choose pressure, force, or speed?

Yes. The kind select splits physical quantities and the unit list follows. Only one kind converts at a time, so you cannot view pressure and force together. Pick the quantity you need first.

Are Pa, bar, atm, psi, and mmHg conversions exact?

Common engineering factors are used. 1 atm = 101325 Pa, 1 bar = 100000 Pa. Weather or medical mercury columns can differ by a digit. Weather hPa is kPa × 10 in place value: 1013 hPa is 101.3 kPa, about 1 atm.

Can I convert N, kgf, and lbf?

Yes. Kilogram-force (kgf), pound-force (lbf), and dyne (dyn) are included. They are not mass in kg. Dynes are old CGS and small; SI reports are better in N.

How do km/h, mph, and knot convert?

All are gathered to m/s then divided. Knot uses about 0.514444 m/s, close to the nautical-mile-per-hour definition. Use the mph row for miles per hour and the knot row for aircraft speed. This is separate from length-in-miles conversion.

Can this tool do length and weight?

No. Use length, weight, and power converters. mm, kg, and W belong there. This page is pressure, force, and speed only.

Can I use it for certified precision measurement?

It is for reference. Calibration and test certificates should follow accredited tables and significant figures. This table’s decimals may be longer than a certificate—follow the certificate at work.

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Last reviewed: 2026-09-04