Lesson 4: Conversions Between SI and Imperial - Conversion Ratios

   Constructing Knowledge

The following tables compare units that are commonly used in both systems of measurement. How do your estimates compare to the values in the tables?
Capacity and Volume: Imperial to SI
Imperial SI
1 UK gallon 4.546 litres
1 US gallon 3.79 litres
1 cubic inch 16.39 cubic centimetres
1 cubic yard 0.765 cubic metres
1 US cup 237 mL
1 UK pint 568 mL
1 US pint 473 mL
Capacity and Volume: SI to Imperial
SI Imperial
1 litre 0.220 UK gallons
1 litre 0.264 US gallons
1 cubic centimetre 0.061 cubic inches
1 cubic metre 1.308 cubic yards
SI Capacity Measure
1 metric cup 250 mL
Length: Imperial to SI
Imperial SI
1 inch 25.4 millimeters
1 inch 2.54 centimetres
1 foot 0.305 metres
1 yard 0.914 metres
1 mile 1.609 kilometres
Length: SI to Imperial
SI Imperial
1 millimetre 0.039 inches
1 centimetre 0.394 inches
1 metre 3.281 feet
1 metre 1.094 yards
1 kilometre 0.621 miles
Mass: Imperial to SI
Imperial SI
1 ounce 28.350 grams
1 pound 0.454 kilograms
Mass: SI to Imperial
SI Imperial
1 gram 0.035 ounces
1 kilogram 2.205 pounds
Area: Imperial to SI
Imperial SI
1 square inch 6.45 square centimetres
1 square foot 0.093 square metres
1 square yard 0.836 square metres
1 square mile 2.59 square kilometres
1 square acre 0.405 hectare
Area: SI to Imperial
SI Imperial
1 square centimetre 0.394 square inches
1 square metre 10.76 square feet
1 square metre 1.196 square yards
1 square kilometre 0.155 square miles
1 hectare 2.471 acres


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