| 0ha | 0b |
| 1ha | 1 × 10³²b |
| 2ha | 2 × 10³²b |
| 3ha | 3 × 10³²b |
| 4ha | 4 × 10³²b |
| 5ha | 5 × 10³²b |
| 6ha | 6 × 10³²b |
| 7ha | 7 × 10³²b |
| 8ha | 8 × 10³²b |
| 9ha | 9 × 10³²b |
| 10ha | 1 × 10³³b |
| 11ha | 1.1 × 10³³b |
| 12ha | 1.2 × 10³³b |
| 13ha | 1.3 × 10³³b |
| 14ha | 1.4 × 10³³b |
| 15ha | 1.5 × 10³³b |
| 16ha | 1.6 × 10³³b |
| 17ha | 1.7 × 10³³b |
| 18ha | 1.8 × 10³³b |
| 19ha | 1.9 × 10³³b |
| 20ha | 2 × 10³³b |
| 21ha | 2.1 × 10³³b |
| 22ha | 2.2 × 10³³b |
| 23ha | 2.3 × 10³³b |
| 24ha | 2.4 × 10³³b |
| 25ha | 2.5 × 10³³b |
| 26ha | 2.6 × 10³³b |
| 27ha | 2.7 × 10³³b |
| 28ha | 2.8 × 10³³b |
| 29ha | 2.9 × 10³³b |
| 30ha | 3 × 10³³b |
| 31ha | 3.1 × 10³³b |
| 32ha | 3.2 × 10³³b |
| 33ha | 3.3 × 10³³b |
| 34ha | 3.4 × 10³³b |
| 35ha | 3.5 × 10³³b |
| 36ha | 3.6 × 10³³b |
| 37ha | 3.7 × 10³³b |
| 38ha | 3.8 × 10³³b |
| 39ha | 3.9 × 10³³b |
| 40ha | 4 × 10³³b |
| 41ha | 4.1 × 10³³b |
| 42ha | 4.2 × 10³³b |
| 43ha | 4.3 × 10³³b |
| 44ha | 4.4 × 10³³b |
| 45ha | 4.5 × 10³³b |
| 46ha | 4.6 × 10³³b |
| 47ha | 4.7 × 10³³b |
| 48ha | 4.8 × 10³³b |
| 49ha | 4.9 × 10³³b |
| 50ha | 5 × 10³³b |
| 51ha | 5.1 × 10³³b |
| 52ha | 5.2 × 10³³b |
| 53ha | 5.3 × 10³³b |
| 54ha | 5.4 × 10³³b |
| 55ha | 5.5 × 10³³b |
| 56ha | 5.6 × 10³³b |
| 57ha | 5.7 × 10³³b |
| 58ha | 5.8 × 10³³b |
| 59ha | 5.9 × 10³³b |
| 60ha | 6 × 10³³b |
| 61ha | 6.1 × 10³³b |
| 62ha | 6.2 × 10³³b |
| 63ha | 6.3 × 10³³b |
| 64ha | 6.4 × 10³³b |
| 65ha | 6.5 × 10³³b |
| 66ha | 6.6 × 10³³b |
| 67ha | 6.7 × 10³³b |
| 68ha | 6.8 × 10³³b |
| 69ha | 6.9 × 10³³b |
| 70ha | 7 × 10³³b |
| 71ha | 7.1 × 10³³b |
| 72ha | 7.2 × 10³³b |
| 73ha | 7.3 × 10³³b |
| 74ha | 7.4 × 10³³b |
| 75ha | 7.5 × 10³³b |
| 76ha | 7.6 × 10³³b |
| 77ha | 7.7 × 10³³b |
| 78ha | 7.8 × 10³³b |
| 79ha | 7.9 × 10³³b |
| 80ha | 8 × 10³³b |
| 81ha | 8.1 × 10³³b |
| 82ha | 8.2 × 10³³b |
| 83ha | 8.3 × 10³³b |
| 84ha | 8.4 × 10³³b |
| 85ha | 8.5 × 10³³b |
| 86ha | 8.6 × 10³³b |
| 87ha | 8.7 × 10³³b |
| 88ha | 8.8 × 10³³b |
| 89ha | 8.9 × 10³³b |
| 90ha | 9 × 10³³b |
| 91ha | 9.1 × 10³³b |
| 92ha | 9.2 × 10³³b |
| 93ha | 9.3 × 10³³b |
| 94ha | 9.4 × 10³³b |
| 95ha | 9.5 × 10³³b |
| 96ha | 9.6 × 10³³b |
| 97ha | 9.7 × 10³³b |
| 98ha | 9.8 × 10³³b |
| 99ha | 9.9 × 10³³b |
The hectare is a unit of area and is a non-SI but metric unit with the symbol ha.
It represents the area equal to that of a square with edges 100m long (ie 1hm² or 10,000m²). This is the equivalent to about 2.47 acres.
Its size is down to its use primary use; that for measuring the size of land.
The barn is a unit of area and is used in particle physics with the symbol b.
It represents approximately the area of the cross-section of a uraneum nucleus, so is very small compared to most other recognised units of area.
It is also used to measure the interaction of a nucleus with an electric field gradient in nuclear quadrupole and magnetic resonance.