| square kilometer | 1 km2 | 2 km2 | 3 km2 | 4 km2 | 5 km2 | 6 km2 | 7 km2 | 8 km2 | 9 km2 | 10 km2 | 11 km2 | 12 km2 | 13 km2 | 14 km2 | 15 km2 | 16 km2 | 17 km2 | 18 km2 | 19 km2 | 20 km2 | 21 km2 | 22 km2 | 23 km2 | 24 km2 | 25 km2 | 26 km2 | 27 km2 | 28 km2 | 29 km2 | 30 km2 | 31 km2 | 32 km2 | 33 km2 | 34 km2 | 35 km2 | 36 km2 | 37 km2 | 38 km2 | 39 km2 | 40 km2 | 41 km2 | 42 km2 | 43 km2 | 44 km2 | 45 km2 | 46 km2 | 47 km2 | 48 km2 | 49 km2 | 50 km2 | 51 km2 | 52 km2 | 53 km2 | 54 km2 | 55 km2 | 56 km2 | 57 km2 | 58 km2 | 59 km2 | 60 km2 | 61 km2 | 62 km2 | 63 km2 | 64 km2 | 65 km2 | 66 km2 | 67 km2 | 68 km2 | 69 km2 | 70 km2 | 71 km2 | 72 km2 | 73 km2 | 74 km2 | 75 km2 | 76 km2 | 77 km2 | 78 km2 | 79 km2 | 80 km2 | 81 km2 | 82 km2 | 83 km2 | 84 km2 | 85 km2 | 86 km2 | 87 km2 | 88 km2 | 89 km2 | 90 km2 | 91 km2 | 92 km2 | 93 km2 | 94 km2 | 95 km2 | 96 km2 | 97 km2 | 98 km2 | 99 km2 | 100 km2 |
| decare | 1 000 Da | 2 000 Da | 3 000 Da | 4 000 Da | 5 000 Da | 6 000 Da | 7 000 Da | 8 000 Da | 9 000 Da | 10 000 Da | 11 000 Da | 12 000 Da | 13 000 Da | 14 000 Da | 15 000 Da | 16 000 Da | 17 000 Da | 18 000 Da | 19 000 Da | 20 000 Da | 21 000 Da | 22 000 Da | 23 000 Da | 24 000 Da | 25 000 Da | 26 000 Da | 27 000 Da | 28 000 Da | 29 000 Da | 30 000 Da | 31 000 Da | 32 000 Da | 33 000 Da | 34 000 Da | 35 000 Da | 36 000 Da | 37 000 Da | 38 000 Da | 39 000 Da | 40 000 Da | 41 000 Da | 42 000 Da | 43 000 Da | 44 000 Da | 45 000 Da | 46 000 Da | 47 000 Da | 48 000 Da | 49 000 Da | 50 000 Da | 51 000 Da | 52 000 Da | 53 000 Da | 54 000 Da | 55 000 Da | 56 000 Da | 57 000 Da | 58 000 Da | 59 000 Da | 60 000 Da | 61 000 Da | 62 000 Da | 63 000 Da | 64 000 Da | 65 000 Da | 66 000 Da | 67 000 Da | 68 000 Da | 69 000 Da | 70 000 Da | 71 000 Da | 72 000 Da | 73 000 Da | 74 000 Da | 75 000 Da | 76 000 Da | 77 000 Da | 78 000 Da | 79 000 Da | 80 000 Da | 81 000 Da | 82 000 Da | 83 000 Da | 84 000 Da | 85 000 Da | 86 000 Da | 87 000 Da | 88 000 Da | 89 000 Da | 90 000 Da | 91 000 Da | 92 000 Da | 93 000 Da | 94 000 Da | 95 000 Da | 96 000 Da | 97 000 Da | 98 000 Da | 99 000 Da | 100 000 Da |
Square kilometre (International spelling as used by the International Bureau of Weights and Measures) or square kilometer (American spelling), symbol km2, is a multiple of the square metre, the SI unit of area or surface area.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| square kilometer | km2 | ≡ 1 km × 1 km | = 106 m2 | Metric system SI |
| square kilometers | decares | square kilometers | decares |
|---|---|---|---|
| 1 | = 1000 | 6 | = 6000 |
| 2 | = 2000 | 7 | = 7000 |
| 3 | = 3000 | 8 | = 8000 |
| 4 | = 4000 | 9 | = 9000 |
| 5 | = 5000 | 10 | = 10000 |
The decare (/ˈdɛkɑːr/ or /ˈdɛkɛər/) is derived from deca and are, and is equal to 10 ares or 1000 square metres. It is used in Norway and in the former Ottoman areas of the Middle East and the Balkans (Bulgaria) as a measure of land area. Instead of the name "decare", the names of traditional land measures are usually used, redefined as one decare:
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| decare | Da | ≡ 1000 m2 | ≡ 1000 m2 | Metric system SI |
| decares | square kilometers | decares | square kilometers |
|---|---|---|---|
| 1 | = 0.001 | 6 | = 0.006 |
| 2 | = 0.002 | 7 | = 0.007 |
| 3 | = 0.003 | 8 | = 0.008 |
| 4 | = 0.004 | 9 | = 0.009 |
| 5 | = 0.005 | 10 | = 0.01 |
| square kilometers | decares |
|---|---|
| 1 | = 1 000 |
| 0.001 | = 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 …) |