| nail (cloth) | 1 nail (cloth) | 2 nail (cloth) | 3 nail (cloth) | 4 nail (cloth) | 5 nail (cloth) | 6 nail (cloth) | 7 nail (cloth) | 8 nail (cloth) | 9 nail (cloth) | 10 nail (cloth) | 11 nail (cloth) | 12 nail (cloth) | 13 nail (cloth) | 14 nail (cloth) | 15 nail (cloth) | 16 nail (cloth) | 17 nail (cloth) | 18 nail (cloth) | 19 nail (cloth) | 20 nail (cloth) | 21 nail (cloth) | 22 nail (cloth) | 23 nail (cloth) | 24 nail (cloth) | 25 nail (cloth) | 26 nail (cloth) | 27 nail (cloth) | 28 nail (cloth) | 29 nail (cloth) | 30 nail (cloth) | 31 nail (cloth) | 32 nail (cloth) | 33 nail (cloth) | 34 nail (cloth) | 35 nail (cloth) | 36 nail (cloth) | 37 nail (cloth) | 38 nail (cloth) | 39 nail (cloth) | 40 nail (cloth) | 41 nail (cloth) | 42 nail (cloth) | 43 nail (cloth) | 44 nail (cloth) | 45 nail (cloth) | 46 nail (cloth) | 47 nail (cloth) | 48 nail (cloth) | 49 nail (cloth) | 50 nail (cloth) | 51 nail (cloth) | 52 nail (cloth) | 53 nail (cloth) | 54 nail (cloth) | 55 nail (cloth) | 56 nail (cloth) | 57 nail (cloth) | 58 nail (cloth) | 59 nail (cloth) | 60 nail (cloth) | 61 nail (cloth) | 62 nail (cloth) | 63 nail (cloth) | 64 nail (cloth) | 65 nail (cloth) | 66 nail (cloth) | 67 nail (cloth) | 68 nail (cloth) | 69 nail (cloth) | 70 nail (cloth) | 71 nail (cloth) | 72 nail (cloth) | 73 nail (cloth) | 74 nail (cloth) | 75 nail (cloth) | 76 nail (cloth) | 77 nail (cloth) | 78 nail (cloth) | 79 nail (cloth) | 80 nail (cloth) | 81 nail (cloth) | 82 nail (cloth) | 83 nail (cloth) | 84 nail (cloth) | 85 nail (cloth) | 86 nail (cloth) | 87 nail (cloth) | 88 nail (cloth) | 89 nail (cloth) | 90 nail (cloth) | 91 nail (cloth) | 92 nail (cloth) | 93 nail (cloth) | 94 nail (cloth) | 95 nail (cloth) | 96 nail (cloth) | 97 nail (cloth) | 98 nail (cloth) | 99 nail (cloth) | 100 nail (cloth) |
| fermi | 57 150 000 000 000 fm | 1.143 × 1014 fm | 1.7145 × 1014 fm | 2.286 × 1014 fm | 2.8575 × 1014 fm | 3.429 × 1014 fm | 4.0005 × 1014 fm | 4.572 × 1014 fm | 5.1435 × 1014 fm | 5.715 × 1014 fm | 6.2865 × 1014 fm | 6.858 × 1014 fm | 7.4295 × 1014 fm | 8.001 × 1014 fm | 8.5725 × 1014 fm | 9.144 × 1014 fm | 9.7155 × 1014 fm | 1.0287 × 1015 fm | 1.08585 × 1015 fm | 1.143 × 1015 fm | 1.20015 × 1015 fm | 1.2573 × 1015 fm | 1.31445 × 1015 fm | 1.3716 × 1015 fm | 1.42875 × 1015 fm | 1.4859 × 1015 fm | 1.54305 × 1015 fm | 1.6002 × 1015 fm | 1.65735 × 1015 fm | 1.7145 × 1015 fm | 1.77165 × 1015 fm | 1.8288 × 1015 fm | 1.88595 × 1015 fm | 1.9431 × 1015 fm | 2.00025 × 1015 fm | 2.0574 × 1015 fm | 2.11455 × 1015 fm | 2.1717 × 1015 fm | 2.22885 × 1015 fm | 2.286 × 1015 fm | 2.34315 × 1015 fm | 2.4003 × 1015 fm | 2.45745 × 1015 fm | 2.5146 × 1015 fm | 2.57175 × 1015 fm | 2.6289 × 1015 fm | 2.68605 × 1015 fm | 2.7432 × 1015 fm | 2.80035 × 1015 fm | 2.8575 × 1015 fm | 2.91465 × 1015 fm | 2.9718 × 1015 fm | 3.02895 × 1015 fm | 3.0861 × 1015 fm | 3.14325 × 1015 fm | 3.2004 × 1015 fm | 3.25755 × 1015 fm | 3.3147 × 1015 fm | 3.37185 × 1015 fm | 3.429 × 1015 fm | 3.48615 × 1015 fm | 3.5433 × 1015 fm | 3.60045 × 1015 fm | 3.6576 × 1015 fm | 3.71475 × 1015 fm | 3.7719 × 1015 fm | 3.82905 × 1015 fm | 3.8862 × 1015 fm | 3.94335 × 1015 fm | 4.0005 × 1015 fm | 4.05765 × 1015 fm | 4.1148 × 1015 fm | 4.17195 × 1015 fm | 4.2291 × 1015 fm | 4.28625 × 1015 fm | 4.3434 × 1015 fm | 4.40055 × 1015 fm | 4.4577 × 1015 fm | 4.51485 × 1015 fm | 4.572 × 1015 fm | 4.62915 × 1015 fm | 4.6863 × 1015 fm | 4.74345 × 1015 fm | 4.8006 × 1015 fm | 4.85775 × 1015 fm | 4.9149 × 1015 fm | 4.97205 × 1015 fm | 5.0292 × 1015 fm | 5.08635 × 1015 fm | 5.1435 × 1015 fm | 5.20065 × 1015 fm | 5.2578 × 1015 fm | 5.31495 × 1015 fm | 5.3721 × 1015 fm | 5.42925 × 1015 fm | 5.4864 × 1015 fm | 5.54355 × 1015 fm | 5.6007 × 1015 fm | 5.65785 × 1015 fm | 5.715 × 1015 fm |
A nail, as a unit of cloth measurement, is generally a sixteenth of a yard or 2 1/4 inches (5.715 cm). The nail was apparently named after the practice of hammering brass nails into the counter at shops where cloth was sold.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| nail (cloth) | ≡ 2 1⁄4 in | = 0.05715 m | Other (Length) |
| nails (cloth) | fermi | nails (cloth) | fermi |
|---|---|---|---|
| 1 | = 57150000000000 | 4 | = 2.286E+14 |
| 1.5 | = 85725000000000 | 4.5 | = 2.57175E+14 |
| 2 | = 1.143E+14 | 5 | = 2.8575E+14 |
| 2.5 | = 1.42875E+14 | 5.5 | = 3.14325E+14 |
| 3 | = 1.7145E+14 | 6 | = 3.429E+14 |
The femtometre (American spelling femtometer, symbol fm derived from the Danish and Norwegian word femten, "fifteen"+Ancient Greek: μέτρον, metrοn, "unit of measurement") is an SI unit of length equal to 10−15 metres, which means a quadrillionth of one. This distance can also be called a fermi and was so named in honour of physicist Enrico Fermi, as it is a typical length-scale of nuclear physics.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| fermi | fm | ≡ 1×10−15 m | ≡ 1×10−15 m | Metric system Non-SI |
| fermi | nails (cloth) | fermi | nails (cloth) |
|---|---|---|---|
| 1 | = 1.7497812773403E-14 | 4 | = 6.9991251093613E-14 |
| 1.5 | = 2.6246719160105E-14 | 4.5 | = 7.8740157480315E-14 |
| 2 | = 3.4995625546807E-14 | 5 | = 8.7489063867017E-14 |
| 2.5 | = 4.3744531933508E-14 | 5.5 | = 9.6237970253718E-14 |
| 3 | = 5.249343832021E-14 | 6 | = 1.0498687664042E-13 |
| nails (cloth) | fermi |
|---|---|
| 1 | = 57 150 000 000 000 |
| 1.7497812773403 × 10-14 | = 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 …) |