SI International System of Units Measurements

Length – SI Base Unit: metre (m)

• 1 millimetre (mm) = 1000 microns (µm or um)
• 1 centimetre (cm) = 10 millimetres (mm)
• 1 decimetre (dm) = 10 centimetres (cm)
• 1 metre (m) = 1000 millimetres (mm)
• 1 kilometre (km) = 1000 metres (m)

Area – SI Base Unit: square metre (m²)

• 1 square centimetre (cm²) = 100 square millimetres (mm²)
• 1 square decimentre (dm²) = 100 square centimetres (cm²)
• 1 square metre (m²) = 1000 square decimetres (dm²)
• 1 square kilometre (km²) = 1,000,000 square metres (m²)

Volume – SI Base Unit: cubic metre (m³)

• 1 cubic centimetre (cm³) = 1 millilitre (mL)
• 1 cubic decimetre (dm³) = 1 litre (L)
• 1 cubic metre (m³) = 1000 litres (L)

Mass – SI Base Unit: kilogram (kg)

• 1 milligram (mg) = 1000 micrograms (ug)
• 1 gram = 1000 milligrams (mg)
• 1 kilogram = 1000 grams (g)
• 1 ton (t) = 1000 kilograms (kg)