| x unit | 1 xu | 2 xu | 3 xu | 4 xu | 5 xu | 6 xu | 7 xu | 8 xu | 9 xu | 10 xu | 11 xu | 12 xu | 13 xu | 14 xu | 15 xu | 16 xu | 17 xu | 18 xu | 19 xu | 20 xu | 21 xu | 22 xu | 23 xu | 24 xu | 25 xu | 26 xu | 27 xu | 28 xu | 29 xu | 30 xu | 31 xu | 32 xu | 33 xu | 34 xu | 35 xu | 36 xu | 37 xu | 38 xu | 39 xu | 40 xu | 41 xu | 42 xu | 43 xu | 44 xu | 45 xu | 46 xu | 47 xu | 48 xu | 49 xu | 50 xu | 51 xu | 52 xu | 53 xu | 54 xu | 55 xu | 56 xu | 57 xu | 58 xu | 59 xu | 60 xu | 61 xu | 62 xu | 63 xu | 64 xu | 65 xu | 66 xu | 67 xu | 68 xu | 69 xu | 70 xu | 71 xu | 72 xu | 73 xu | 74 xu | 75 xu | 76 xu | 77 xu | 78 xu | 79 xu | 80 xu | 81 xu | 82 xu | 83 xu | 84 xu | 85 xu | 86 xu | 87 xu | 88 xu | 89 xu | 90 xu | 91 xu | 92 xu | 93 xu | 94 xu | 95 xu | 96 xu | 97 xu | 98 xu | 99 xu | 100 xu |
| fathom | 5.4795494313211 × 10-14 ftm | 1.0959098862642 × 10-13 ftm | 1.6438648293963 × 10-13 ftm | 2.1918197725284 × 10-13 ftm | 2.7397747156605 × 10-13 ftm | 3.2877296587927 × 10-13 ftm | 3.8356846019248 × 10-13 ftm | 4.3836395450569 × 10-13 ftm | 4.931594488189 × 10-13 ftm | 5.4795494313211 × 10-13 ftm | 6.0275043744532 × 10-13 ftm | 6.5754593175853 × 10-13 ftm | 7.1234142607174 × 10-13 ftm | 7.6713692038495 × 10-13 ftm | 8.2193241469816 × 10-13 ftm | 8.7672790901137 × 10-13 ftm | 9.3152340332458 × 10-13 ftm | 9.863188976378 × 10-13 ftm | 1.041114391951 × 10-12 ftm | 1.0959098862642 × 10-12 ftm | 1.1507053805774 × 10-12 ftm | 1.2055008748906 × 10-12 ftm | 1.2602963692038 × 10-12 ftm | 1.3150918635171 × 10-12 ftm | 1.3698873578303 × 10-12 ftm | 1.4246828521435 × 10-12 ftm | 1.4794783464567 × 10-12 ftm | 1.5342738407699 × 10-12 ftm | 1.5890693350831 × 10-12 ftm | 1.6438648293963 × 10-12 ftm | 1.6986603237095 × 10-12 ftm | 1.7534558180227 × 10-12 ftm | 1.808251312336 × 10-12 ftm | 1.8630468066492 × 10-12 ftm | 1.9178423009624 × 10-12 ftm | 1.9726377952756 × 10-12 ftm | 2.0274332895888 × 10-12 ftm | 2.082228783902 × 10-12 ftm | 2.1370242782152 × 10-12 ftm | 2.1918197725284 × 10-12 ftm | 2.2466152668416 × 10-12 ftm | 2.3014107611549 × 10-12 ftm | 2.3562062554681 × 10-12 ftm | 2.4110017497813 × 10-12 ftm | 2.4657972440945 × 10-12 ftm | 2.5205927384077 × 10-12 ftm | 2.5753882327209 × 10-12 ftm | 2.6301837270341 × 10-12 ftm | 2.6849792213473 × 10-12 ftm | 2.7397747156605 × 10-12 ftm | 2.7945702099738 × 10-12 ftm | 2.849365704287 × 10-12 ftm | 2.9041611986002 × 10-12 ftm | 2.9589566929134 × 10-12 ftm | 3.0137521872266 × 10-12 ftm | 3.0685476815398 × 10-12 ftm | 3.123343175853 × 10-12 ftm | 3.1781386701662 × 10-12 ftm | 3.2329341644794 × 10-12 ftm | 3.2877296587927 × 10-12 ftm | 3.3425251531059 × 10-12 ftm | 3.3973206474191 × 10-12 ftm | 3.4521161417323 × 10-12 ftm | 3.5069116360455 × 10-12 ftm | 3.5617071303587 × 10-12 ftm | 3.6165026246719 × 10-12 ftm | 3.6712981189851 × 10-12 ftm | 3.7260936132983 × 10-12 ftm | 3.7808891076115 × 10-12 ftm | 3.8356846019248 × 10-12 ftm | 3.890480096238 × 10-12 ftm | 3.9452755905512 × 10-12 ftm | 4.0000710848644 × 10-12 ftm | 4.0548665791776 × 10-12 ftm | 4.1096620734908 × 10-12 ftm | 4.164457567804 × 10-12 ftm | 4.2192530621172 × 10-12 ftm | 4.2740485564304 × 10-12 ftm | 4.3288440507437 × 10-12 ftm | 4.3836395450569 × 10-12 ftm | 4.4384350393701 × 10-12 ftm | 4.4932305336833 × 10-12 ftm | 4.5480260279965 × 10-12 ftm | 4.6028215223097 × 10-12 ftm | 4.6576170166229 × 10-12 ftm | 4.7124125109361 × 10-12 ftm | 4.7672080052493 × 10-12 ftm | 4.8220034995626 × 10-12 ftm | 4.8767989938758 × 10-12 ftm | 4.931594488189 × 10-12 ftm | 4.9863899825022 × 10-12 ftm | 5.0411854768154 × 10-12 ftm | 5.0959809711286 × 10-12 ftm | 5.1507764654418 × 10-12 ftm | 5.205571959755 × 10-12 ftm | 5.2603674540682 × 10-12 ftm | 5.3151629483815 × 10-12 ftm | 5.3699584426947 × 10-12 ftm | 5.4247539370079 × 10-12 ftm | 5.4795494313211 × 10-12 ftm |
The x unit (symbol xu) is a unit of length approximately equal to 0.1 pm (10−13 m). It is used to quote the wavelength of X-rays and gamma rays.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| x unit | xu | ≈ 1.0021×10−13 m | ≈ 1.0021×10−13 m | Metric system Non-SI |
| x units | fathoms | x units | fathoms |
|---|---|---|---|
| 1 | ≈ 5.4795494313211E-14 | 4 | ≈ 2.1918197725284E-13 |
| 1.5 | ≈ 8.2193241469816E-14 | 4.5 | ≈ 2.4657972440945E-13 |
| 2 | ≈ 1.0959098862642E-13 | 5 | ≈ 2.7397747156605E-13 |
| 2.5 | ≈ 1.3698873578303E-13 | 5.5 | ≈ 3.0137521872266E-13 |
| 3 | ≈ 1.6438648293963E-13 | 6 | ≈ 3.2877296587927E-13 |
A fathom is a unit of length in the imperial and the U.S. customary systems equal to 6 feet (1.8288 metres), used especially for measuring the depth of water.
There are two yards (6 feet) in an imperial fathom. Originally the span of a man's outstretched arms, the size of a fathom has varied slightly depending on whether it was defined as a thousandth of an (Admiralty) nautical mile or as a multiple of the imperial yard. Formerly, the term was used for any of several units of length varying around 5–5 1⁄2 feet.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| fathom | ftm | ≡ 6 ft | = 1.8288 m | Imperial/US |
| fathoms | x units | fathoms | x units |
|---|---|---|---|
| 1 | ≈ 18249675681070 | 4 | ≈ 72998702724279 |
| 1.5 | ≈ 27374513521605 | 4.5 | ≈ 82123540564814 |
| 2 | ≈ 36499351362140 | 5 | ≈ 91248378405349 |
| 2.5 | ≈ 45624189202674 | 5.5 | ≈ 1.0037321624588E+14 |
| 3 | ≈ 54749027043209 | 6 | ≈ 1.0949805408642E+14 |
| x units | fathoms |
|---|---|
| 1 | ≈ 5.4795494313211 × 10-14 |
| 18 249 675 681 070 | ≈ 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 …) |