| circular mil | 1 circ mil | 2 circ mil | 3 circ mil | 4 circ mil | 5 circ mil | 6 circ mil | 7 circ mil | 8 circ mil | 9 circ mil | 10 circ mil | 11 circ mil | 12 circ mil | 13 circ mil | 14 circ mil | 15 circ mil | 16 circ mil | 17 circ mil | 18 circ mil | 19 circ mil | 20 circ mil | 21 circ mil | 22 circ mil | 23 circ mil | 24 circ mil | 25 circ mil | 26 circ mil | 27 circ mil | 28 circ mil | 29 circ mil | 30 circ mil | 31 circ mil | 32 circ mil | 33 circ mil | 34 circ mil | 35 circ mil | 36 circ mil | 37 circ mil | 38 circ mil | 39 circ mil | 40 circ mil | 41 circ mil | 42 circ mil | 43 circ mil | 44 circ mil | 45 circ mil | 46 circ mil | 47 circ mil | 48 circ mil | 49 circ mil | 50 circ mil | 51 circ mil | 52 circ mil | 53 circ mil | 54 circ mil | 55 circ mil | 56 circ mil | 57 circ mil | 58 circ mil | 59 circ mil | 60 circ mil | 61 circ mil | 62 circ mil | 63 circ mil | 64 circ mil | 65 circ mil | 66 circ mil | 67 circ mil | 68 circ mil | 69 circ mil | 70 circ mil | 71 circ mil | 72 circ mil | 73 circ mil | 74 circ mil | 75 circ mil | 76 circ mil | 77 circ mil | 78 circ mil | 79 circ mil | 80 circ mil | 81 circ mil | 82 circ mil | 83 circ mil | 84 circ mil | 85 circ mil | 86 circ mil | 87 circ mil | 88 circ mil | 89 circ mil | 90 circ mil | 91 circ mil | 92 circ mil | 93 circ mil | 94 circ mil | 95 circ mil | 96 circ mil | 97 circ mil | 98 circ mil | 99 circ mil | 100 circ mil |
| barn | 5.067075 × 1018 b | 1.013415 × 1019 b | 1.5201225 × 1019 b | 2.02683 × 1019 b | 2.5335375 × 1019 b | 3.040245 × 1019 b | 3.5469525 × 1019 b | 4.05366 × 1019 b | 4.5603675 × 1019 b | 5.067075 × 1019 b | 5.5737825 × 1019 b | 6.08049 × 1019 b | 6.5871975 × 1019 b | 7.093905 × 1019 b | 7.6006125 × 1019 b | 8.10732 × 1019 b | 8.6140275 × 1019 b | 9.120735 × 1019 b | 9.6274425 × 1019 b | 1.013415 × 1020 b | 1.06408575 × 1020 b | 1.1147565 × 1020 b | 1.16542725 × 1020 b | 1.216098 × 1020 b | 1.26676875 × 1020 b | 1.3174395 × 1020 b | 1.36811025 × 1020 b | 1.418781 × 1020 b | 1.46945175 × 1020 b | 1.5201225 × 1020 b | 1.57079325 × 1020 b | 1.621464 × 1020 b | 1.67213475 × 1020 b | 1.7228055 × 1020 b | 1.77347625 × 1020 b | 1.824147 × 1020 b | 1.87481775 × 1020 b | 1.9254885 × 1020 b | 1.97615925 × 1020 b | 2.02683 × 1020 b | 2.07750075 × 1020 b | 2.1281715 × 1020 b | 2.17884225 × 1020 b | 2.229513 × 1020 b | 2.28018375 × 1020 b | 2.3308545 × 1020 b | 2.38152525 × 1020 b | 2.432196 × 1020 b | 2.48286675 × 1020 b | 2.5335375 × 1020 b | 2.58420825 × 1020 b | 2.634879 × 1020 b | 2.68554975 × 1020 b | 2.7362205 × 1020 b | 2.78689125 × 1020 b | 2.837562 × 1020 b | 2.88823275 × 1020 b | 2.9389035 × 1020 b | 2.98957425 × 1020 b | 3.040245 × 1020 b | 3.09091575 × 1020 b | 3.1415865 × 1020 b | 3.19225725 × 1020 b | 3.242928 × 1020 b | 3.29359875 × 1020 b | 3.3442695 × 1020 b | 3.39494025 × 1020 b | 3.445611 × 1020 b | 3.49628175 × 1020 b | 3.5469525 × 1020 b | 3.59762325 × 1020 b | 3.648294 × 1020 b | 3.69896475 × 1020 b | 3.7496355 × 1020 b | 3.80030625 × 1020 b | 3.850977 × 1020 b | 3.90164775 × 1020 b | 3.9523185 × 1020 b | 4.00298925 × 1020 b | 4.05366 × 1020 b | 4.10433075 × 1020 b | 4.1550015 × 1020 b | 4.20567225 × 1020 b | 4.256343 × 1020 b | 4.30701375 × 1020 b | 4.3576845 × 1020 b | 4.40835525 × 1020 b | 4.459026 × 1020 b | 4.50969675 × 1020 b | 4.5603675 × 1020 b | 4.61103825 × 1020 b | 4.661709 × 1020 b | 4.71237975 × 1020 b | 4.7630505 × 1020 b | 4.81372125 × 1020 b | 4.864392 × 1020 b | 4.91506275 × 1020 b | 4.9657335 × 1020 b | 5.01640425 × 1020 b | 5.067075 × 1020 b |
A circular mil is a unit of area, equal to the area of a circle with a diameter of one mil (one thousandth of an inch). It corresponds to 5.067×10−4 mm². It is a unit intended for referring to the area of a wire with a circular cross section. As the area in circular mils can be calculated without reference to π, the unit makes conversion between cross section and diameter of a wire considerably easier.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| circular mil | circ mil | ≡ π⁄4 mil2 | ≈ 5.067075×10−10 m2 | Imperial/US |
| circular mils | barns | circular mils | barns |
|---|---|---|---|
| 1 | = 5.067075E+18 | 6 | = 3.040245E+19 |
| 2 | = 1.013415E+19 | 7 | = 3.5469525E+19 |
| 3 | = 1.5201225E+19 | 8 | = 4.05366E+19 |
| 4 | = 2.02683E+19 | 9 | = 4.5603675E+19 |
| 5 | = 2.5335375E+19 | 10 | = 5.067075E+19 |
A barn (symbol: b) is a unit of area equal to 10−28 m2 (100 fm2). Originally used in nuclear physics for expressing the cross sectional area of nuclei and nuclear reactions, today it is also used in all fields of high-energy physics to express the cross sections of any scattering process, and is best understood as a measure of the probability of interaction between small particles.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| barn | b | ≡ 10−28 m2 | ≡ 10−28 m2 | Nuclear Physics |
| barns | circular mils | barns | circular mils |
|---|---|---|---|
| 1 | = 1.9735251599789E-19 | 6 | = 1.1841150959873E-18 |
| 2 | = 3.9470503199578E-19 | 7 | = 1.3814676119852E-18 |
| 3 | = 5.9205754799366E-19 | 8 | = 1.5788201279831E-18 |
| 4 | = 7.8941006399155E-19 | 9 | = 1.776172643981E-18 |
| 5 | = 9.8676257998944E-19 | 10 | = 1.9735251599789E-18 |
| circular mils | barns |
|---|---|
| 1 | = 5.067075 × 1018 |
| 1.9735251599789 × 10-19 | = 1 |
| Symbol | Definition |
|---|---|
| ≡ | exactly equal |
| ≈ | approximately equal to |
| = | equal to |
| digits | indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …) |