| foot | 1 ft | 2 ft | 3 ft | 4 ft | 5 ft | 6 ft | 7 ft | 8 ft | 9 ft | 10 ft | 11 ft | 12 ft | 13 ft | 14 ft | 15 ft | 16 ft | 17 ft | 18 ft | 19 ft | 20 ft | 21 ft | 22 ft | 23 ft | 24 ft | 25 ft | 26 ft | 27 ft | 28 ft | 29 ft | 30 ft | 31 ft | 32 ft | 33 ft | 34 ft | 35 ft | 36 ft | 37 ft | 38 ft | 39 ft | 40 ft | 41 ft | 42 ft | 43 ft | 44 ft | 45 ft | 46 ft | 47 ft | 48 ft | 49 ft | 50 ft | 51 ft | 52 ft | 53 ft | 54 ft | 55 ft | 56 ft | 57 ft | 58 ft | 59 ft | 60 ft | 61 ft | 62 ft | 63 ft | 64 ft | 65 ft | 66 ft | 67 ft | 68 ft | 69 ft | 70 ft | 71 ft | 72 ft | 73 ft | 74 ft | 75 ft | 76 ft | 77 ft | 78 ft | 79 ft | 80 ft | 81 ft | 82 ft | 83 ft | 84 ft | 85 ft | 86 ft | 87 ft | 88 ft | 89 ft | 90 ft | 91 ft | 92 ft | 93 ft | 94 ft | 95 ft | 96 ft | 97 ft | 98 ft | 99 ft | 100 ft |
| fermi | 3.048 × 1014 fm | 6.096 × 1014 fm | 9.144 × 1014 fm | 1.2192 × 1015 fm | 1.524 × 1015 fm | 1.8288 × 1015 fm | 2.1336 × 1015 fm | 2.4384 × 1015 fm | 2.7432 × 1015 fm | 3.048 × 1015 fm | 3.3528 × 1015 fm | 3.6576 × 1015 fm | 3.9624 × 1015 fm | 4.2672 × 1015 fm | 4.572 × 1015 fm | 4.8768 × 1015 fm | 5.1816 × 1015 fm | 5.4864 × 1015 fm | 5.7912 × 1015 fm | 6.096 × 1015 fm | 6.4008 × 1015 fm | 6.7056 × 1015 fm | 7.0104 × 1015 fm | 7.3152 × 1015 fm | 7.62 × 1015 fm | 7.9248 × 1015 fm | 8.2296 × 1015 fm | 8.5344 × 1015 fm | 8.8392 × 1015 fm | 9.144 × 1015 fm | 9.4488 × 1015 fm | 9.7536 × 1015 fm | 1.00584 × 1016 fm | 1.03632 × 1016 fm | 1.0668 × 1016 fm | 1.09728 × 1016 fm | 1.12776 × 1016 fm | 1.15824 × 1016 fm | 1.18872 × 1016 fm | 1.2192 × 1016 fm | 1.24968 × 1016 fm | 1.28016 × 1016 fm | 1.31064 × 1016 fm | 1.34112 × 1016 fm | 1.3716 × 1016 fm | 1.40208 × 1016 fm | 1.43256 × 1016 fm | 1.46304 × 1016 fm | 1.49352 × 1016 fm | 1.524 × 1016 fm | 1.55448 × 1016 fm | 1.58496 × 1016 fm | 1.61544 × 1016 fm | 1.64592 × 1016 fm | 1.6764 × 1016 fm | 1.70688 × 1016 fm | 1.73736 × 1016 fm | 1.76784 × 1016 fm | 1.79832 × 1016 fm | 1.8288 × 1016 fm | 1.85928 × 1016 fm | 1.88976 × 1016 fm | 1.92024 × 1016 fm | 1.95072 × 1016 fm | 1.9812 × 1016 fm | 2.01168 × 1016 fm | 2.04216 × 1016 fm | 2.07264 × 1016 fm | 2.10312 × 1016 fm | 2.1336 × 1016 fm | 2.16408 × 1016 fm | 2.19456 × 1016 fm | 2.22504 × 1016 fm | 2.25552 × 1016 fm | 2.286 × 1016 fm | 2.31648 × 1016 fm | 2.34696 × 1016 fm | 2.37744 × 1016 fm | 2.40792 × 1016 fm | 2.4384 × 1016 fm | 2.46888 × 1016 fm | 2.49936 × 1016 fm | 2.52984 × 1016 fm | 2.56032 × 1016 fm | 2.5908 × 1016 fm | 2.62128 × 1016 fm | 2.65176 × 1016 fm | 2.68224 × 1016 fm | 2.71272 × 1016 fm | 2.7432 × 1016 fm | 2.77368 × 1016 fm | 2.80416 × 1016 fm | 2.83464 × 1016 fm | 2.86512 × 1016 fm | 2.8956 × 1016 fm | 2.92608 × 1016 fm | 2.95656 × 1016 fm | 2.98704 × 1016 fm | 3.01752 × 1016 fm | 3.048 × 1016 fm |
The foot (pl. feet; abbreviation: ft; symbol: ′, the prime symbol) is a unit of length in the imperial and US customary systems of measurement. Since 1959, both units have been defined by international agreement as equivalent to 0.3048 meters exactly. In both systems, the foot comprises 12 inches and three feet compose a yard.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| foot | ft | ≡ 0.3048 m ≡ 1⁄3 yd ≡ 12 inches | ≡ 0.3048 m | Imperial/US |
| feet | fermi | feet | fermi |
|---|---|---|---|
| 1 | ≡ 3.048E+14 | 4 | ≡ 1.2192E+15 |
| 1.5 | ≡ 4.572E+14 | 4.5 | ≡ 1.3716E+15 |
| 2 | ≡ 6.096E+14 | 5 | ≡ 1.524E+15 |
| 2.5 | ≡ 7.62E+14 | 5.5 | ≡ 1.6764E+15 |
| 3 | ≡ 9.144E+14 | 6 | ≡ 1.8288E+15 |
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 | feet | fermi | feet |
|---|---|---|---|
| 1 | ≡ 3.2808398950131E-15 | 4 | ≡ 1.3123359580052E-14 |
| 1.5 | ≡ 4.9212598425197E-15 | 4.5 | ≡ 1.4763779527559E-14 |
| 2 | ≡ 6.5616797900262E-15 | 5 | ≡ 1.6404199475066E-14 |
| 2.5 | ≡ 8.2020997375328E-15 | 5.5 | ≡ 1.8044619422572E-14 |
| 3 | ≡ 9.8425196850394E-15 | 6 | ≡ 1.9685039370079E-14 |
| feet | fermi |
|---|---|
| 1 | ≡ 3.048 × 1014 |
| 3.2808398950131 × 10-15 | ≡ 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 …) |