Units of Area
The fundamental unit for measuring area is the square meter, which is the area of a square whose sides measure 1 meter.
There are also other units for measuring large and small quantities of area:
| square kilometer | km2 | 1,000,000 m2 |
| square hectometer | hm2 | 10,000 m2 |
| square decameter | dam2 | 100 m2 |
| square meter | m2 | 1 m2 |
| square decimeter | dm2 | 0.01 m2 |
| square centimeter | cm2 | 0.0001 m2 |
| square milimeter | mm2 | 0.000001 m2 |
Note that each unit is 100 times larger than the previous.
Therefore, the problem of converting units to other units becomes an issue of multiplying or dividing the unit by one followed by as many pairs of zeros as there are places between them.
1.5 hm2 
m2
In this case, multiply (because the hm2 is greater than the m2) the unit by one followed by four zeros, since there are two places between both units.
1.5 · 10,000 = 15,000 m2
15,000 mm2 m2
In this case, divide (because the mm2 is smaller than the m2) by one followed by six zeros, since there are three places between both units.
15.000 : 1,000,000 = 0.015 m2
Examples
Land Area Measurements
Hectare
The hectare is equivalent to the square hectometer.
1 ha = 1 hm2 = 10,000 m²
Are
The are is equivalent to the square decameter.
1 a = 1 dam2 = 100 m²
Centiare
The centiare is equivalent to the square meter.
1 ca = 1 m²
Convert to hectares:
211,943 a
211,943 : 100 = 2,119.43 ha
356,500 m2
356,500 : 10,000 = 35.65 hm2 = 35.65 ha
0.425 km2
0.425 · 100 = 42.5 hm2 = 42.5 ha
8 km2 31 hm2 50 dam2
8 · 100 + 31 + 50 : 100 = 731.5 hm2 = 831.5 ha
91 m2 33 dm2 10 cm2 =
91 : 10,000 + 33 : 1,000,000 + 10 : 100,000,000=
0.00913310 hm2 = 0.00913310 ha
