Common units and conversions
You may also be interested in our units for magnetic properties page
Temperature
Fahrenheit to Celsius: °C = (°F-32)/1.8
Celsius to Fahrenheit: °F = (1.8 × °C) + 32
Fahrenheit to Kelvin: convert °F to °C, then add 273.15
Celsius to Kelvin: add 273.15
Volume
1 liter (L) = 1.000 × 10–3 cubic meters (m3) = 61.02 cubic inches (in3)
Mass
1 kilogram (kg) = 1000 grams (g) = 2.205 pounds (lb)
Force
1 newton (N) = 0.2248 pounds (lb)
Electric resistivity
1 micro-ohm-centimeter (µΩ·cm)
= 1.000 × 10–6 ohm-centimeter (Ω·cm)
= 1.000 × 10–8 ohm-meter (Ω·m)
= 6.015 ohm-circular mil per foot (Ω·circ mil/ft)
Heat flow rate
1 watt (W) = 3.413 Btu/h
1 British thermal unit per hour (Btu/h) = 0.2930 W
A note on SI
The values on this website are expressed in International System of Units, or SI (from the French Le Système International d’Unités). When possible, the common CGS or British equivalent has been parenthetically included as well.
These common conversions and constants have been included as a reference.
Please refer to NIST Special Publication 811 for further standards and conversions.
Ambler Thompson and Barry N. Taylor (2008), Guide for the Use of the International System of Units (SI) NIST Special Publication 811, 2008 Edition (version 3.2). [Online] Available: http://physics.nist.gov/SP811 [2023, Aug 3]. National Institute of Standards and Technology, Gaithersburg, MD.
Length
| centimeter (cm) | meter (m) | inch (in) | |
|---|---|---|---|
| centimeter (cm) | 1 | 1.000 × 10-2 | 0.3937 |
| meter (m) | 100 | 1 | 39.37 |
| inch (in) | 2.540 | 2.540 × 10-2 | 1 |
1 micrometer (sometimes referred to as micron) = 10-6 m
1 mil = 10-3 in
Area
| cm2 | m2 | in2 | circ mil | |
|---|---|---|---|---|
| cm2 | 1 | 10-4 | 0.1550 | 1.974 × 105 |
| m2 | 104 | 1 | 1550 | 1.974 × 109 |
| in2 | 6.452 | 6.452 × 10-4 | 1 | 1.273 × 106 |
| circ mil | 5.067 × 10-6 | 5.067 × 10–10 | 7.854 × 10-7 | 1 |
Pressure
| pascal (Pa) | millibar (mbar) | torr (Torr) | atmosphere (atm) | psi (lbf/in2) | |
|---|---|---|---|---|---|
| pascal (Pa) | 1 | 1.000 × 10–2 | 7.501 × 10–3 | 9.868 × 10–6 | 1.450 × 10–4 |
| millibar (mbar) | 1.000 × 102 | 1 | 7.502 × 10–1 | 9.868 × 10–4 | 1.450 × 10–2 |
| torr (Torr) | 1.333 × 102 | 1.333 × 100 | 1 | 1.316 × 10–3 | 1.934 × 10–2 |
| atmosphere (atm) | 1.013 × 105 | 1.013 × 103 | 7.600 × 102 | 1 | 1.470 × 101 |
| psi (lbf/in2) | 6.897 × 103 | 6.895 × 101 | 5.172 × 101 | 6.850 × 10–2 | 1 |
133.332 pascal (Pa)
1.33 millibar (mbar)
0.001316 atmosphere (atm)
0.01934 psi (lbf/in2)
0.01 millibar (mbar)
0.007501 torr (Torr)
9.87 × 10–6 atmosphere (atm)
1.45 × 10–4 psi (lbf/in2)
Magnetic induction B
| gauss (G) | kiloline/in2 | Wb/m2 | milligauss (mG) | gamma (γ) | |
|---|---|---|---|---|---|
| gauss (G) | 1 | 6.452 × 10–3 | 10–4 | 1000 | 105 |
| kiloline/in2 | 155.0 | 1 | 1.550 × 10–2 | 1.550 × 105 | 1.550 × 107 |
| Wb/m2 | 104 | 64.52 | 1 | 107 | 109 |
| milligauss (mG) | 0.001 | 6.452 × 10–6 | 10–7 | 1 | 100 |
| gamma (γ) | 10–5 | 6.452 × 10–8 | 10–9 | 0.01 | 1 |
1 ESU = 2.998 × 106 Wb/m2
Magnetomotive force
| abampere·turn | ampere·turn | Gilbert (Gi) | |
|---|---|---|---|
| abampere·turn | 1 | 10 | 12.57 |
| ampere·turn | 0.1 | 1 | 1.257 |
| Gilbert (Gi) | 7.958 × 10–2 | 0.7958 | 1 |
1 pragilbert = 4π ampere·turn
1 ESU = 2.655 × 10–11 ampere·turn
Magnetic field strength H
| abampere·turn/cm | ampere·turn/cm | ampere·turn/in | ampere·turn/m | oersted (Oe) | |
|---|---|---|---|---|---|
| abampere·turn/cm | 1 | 10 | 25.40 | 1000 | 12.57 |
| ampere·turn/cm | 0.1 | 1 | 2.540 | 100 | 1.257 |
| ampere·turn/in | 3.937 × 10–2 | 0.3937 | 1 | 39.37 | 0.4947 |
| ampere·turn/m | 0.001 | 0.01 | 2.540 × 10–2 | 1 | 1.257 × 10–2 |
| oersted (Oe) | 7.958 × 10–2 | 0.7958 | 2.021 | 79.58 | 1 |
1 Oe = 1 Gi
1 ESU = 2.655 × 10–9 ampere·turn/m
1 praoersted = 4π ampere·turn/m
Energy, work, heat
| Btu | erg | J | cal | kW·h | |
|---|---|---|---|---|---|
| Btu | 1 | 1.055 × 1010 | 1055 | 252.0 | 2.930 × 10–4 |
| erg | 9.481 × 10–11 | 1 | 10–7 | 2.389 × 10–8 | 2.778 × 10–14 |
| J | 9.481 × 10–4 | 107 | 1 | 0.2389 | 2.778 × 10–7 |
| cal | 3.968 × 10–3 | 4.186 × 107 | 4.186 | 1 | 1.163 × 10–6 |
| kW·h | 3413 | 3.6 × 1013 | 3.6 × 106 | 8.601 × 105 | 1 |
1 electronvolt (eV) = 1.602 × 10–19 joules (J)
Fundamental physical constants
| Symbol | Value* | Unit | |
|---|---|---|---|
| speed of light in a vacuum | c, c0 | 299 792 458 | m · s–1 |
| magnetic constant | µ0 | 4π × 10–7 = 12.566 370 614... × 10–7 | N · A–2 |
| electric constant 1/µ0c2 | ε0 | 8.854 187 817... × 10–12 | F · m–1 |
| characteristic impedance of vacuum √µ0 /∈0 = µ0c |
Z0 | 376.730 313 461... | Ω |
| Planck constant in eV · s h/2π in eV · s |
h | 6.626 0693(11) × 10–34 4.135 667 43(35) × 10–15 1.054 571 68(18) × 10–34 6.582 119 15(56) × 10–16 |
J · s eV · s J · s eV · s |
| elementary charge | e | 1.602 176 53(14) × 10–19 | C |
| magnetic flux quantum h/2e | Φ0 | 2.067 833 72(18) × 10–15 | Wb |
| Avogadro constant | NA, L | 6.022 1415(10) × 1023 | mol–1 |
| atomic mass constant mu = ⅟₁₂m(12C) = 1 u | mu | 1.660 538 86(28) × 10–27 | kg |
| Faraday constant NA e | F | 96 485.3383(83) | C · mol–1 |
| molar gas constant | R | 8.314 472(15) | J · mol–1 · K–1 |
| Boltzmann constant R/NA | k | 1.380 650 5(24) × 10–23 | J · K–1 |
| molar volume of ideal gas RT / p T = 273.15 K, p = 101.325 kPa T = 273.15 K, p = 100 kPa |
Vm | 22.413 996(39) × 10–3 22.710 981(40) × 10–3 |
m3 · mol–1 m3 · mol–1 |
| Stefan-Boltzmann constant (π2/60)k4/h3c2 | σ | 5.670 400(40) × 10–8 | W · m–2 · K–4 |
| electron volt: (e/C) J | eV | 1.602 176 53(14) × 10–19 | J |
| Bohr magneton eh/2me in eV · T–1 [µB/(J · T–1)](e/C) |
µB | 927.400 949(80) × 10–26 5.788 381 804(39) × 10–5 |
J · T–1 eV · T–1 |
*Values are shown in their concise form with uncertainty in parentheses. Numbers with uncertainty values are subject to revision. Refer to the NIST Reference on Constants, Units, and Uncertainty website for the latest values