Imperial units


Like metric system units, imperial units are used to measure quantities such as mass, distance, area, volume/capacity and speed.


They include pounds, yards, square and cubic yards, imperial gallons and miles per hour.


Converting between imperial units



Mass

Conversion

factor

Example

Imperial tons to stones

(imperial tons to st)

x 160

1 imperial ton

= 1 x 160

= 160 stones

Stones to imperial tons

(st to imperial tons)

÷ 160

160 stones

= 160 ÷ 160

= 1 imperial ton

Stones to pounds

(st to lb)

x 14

1st = 1 x 14 = 14lb

Pounds to stones

(lb to st)

÷ 14

14lb = 14 ÷ 14 = 1st

Pounds to ounces

(lb to oz)

x 16

1lb = 1 x 16 = 16oz

Ounces to pounds

(oz to lb)


÷ 16

16oz = 16 ÷ 16 = 1lb



Distance (length/height/width)

Conversion

factor

Example

Miles to yards

(miles to yd)

x 1760

1 mile = 1 x 1760 = 1760yd

Yards to miles

(yd to miles)

÷ 1760

1760yd = 1760 ÷ 1760 = 1 mile

Yards to feet

(yd to ft)

x 3

1yd = 1 x 3 = 3ft

Feet to yards

(ft to yd)

÷ 3

3ft = 3 ÷ 3 = 1yd

Feet to inches

(ft to in)

x 12

1ft = 1 x 12 = 12in

Inches to feet

(in to ft)

÷ 12

12in = 12 ÷ 12 = 1ft



Area

Conversion

factor

Example

Acres to square yards

(ac to yd²)

x 4840

1ac = 1 x 4840 = 4840yd²

Square yards to acres

(yd² to ac)

÷ 4840

4840yd² = 4840 ÷ 4840 = 1ac

Square yards

to square feet

(yd² to ft²)

x 9

1yd² = 1 x 9 = 9ft²

Square feet

to square yards

(ft² to yd²)

÷ 9

9ft² = 9 ÷ 9 = 1yd²

Square feet

to square inches

(ft² to in²)

x 144

1ft² = 1 x 144 = 144in²

Square inches

to square feet

(in² to ft²)

÷ 144

144in² = 144 ÷ 144 = 1ft²

Note

  • 1yd² = 1yd x 1yd = 3ft x 3ft = 9ft²
  • 1ft² = 1ft x 1ft = 12in x 12in = 144in²



Volume / capacity

Conversion

factor

Example

Cubic yards to cubic feet

(yd³ to ft³)

x 27

1yd³ = 1 x 27 = 27ft³

Cubic feet to cubic yards

(ft³ to yd³)

÷ 27

27ft³ = 27 ÷ 27= 1yd³

Cubic feet to cubic inches

(ft³ to in³)

x 1728

1ft³ = 1 x 1728 = 1728in³

Cubic inches to cubic feet

(in³ to ft³)

÷ 1728

1728in³ = 1728 ÷ 1728 = 1ft³

Imperial gallons

to imperial pints

(imp gal to imp pt)

x 8

1 imp gal = 1 x 8 = 8 imp pt

Imperial pints

to imperial gallons

(imp pt to imp gal)

÷ 8

8 imp pt = 8 ÷ 8 = 1 imp gal

Note

  • 1yd³ = 1yd x 1yd x 1yd = 3ft x 3ft x 3ft = 27ft³
  • 1ft³ = 1ft x 1ft x 1ft = 12in x 12in x 12in = 1728in³

Also

  • imperial gallon ~4.546l, imperial pint ~0.568l
  • US gallon ~3.785l, US pint ~ 0.473l



Speed

Conversion

factor

Example

Miles per hour

to yards per second

(yd/s to mph)

÷ 2.045

(approx)

2.045mph

= 2.045 ÷ 2.045

= 1yd/s

Yards per second

to miles per hour

(yd/s to mph)

x 2.045

(approx)

1yd/s = 1 x 2.045 = 2.045mph

Miles per hour

to feet per second

(mph to ft/s)

÷ 0.682

(approx)

0.682mph

= 0.682 ÷ 0.682

= 1ft/s

Feet per second

to miles per hour

(ft/s to mph)

x 0.682

(approx)

1ft/s = 1 x 0.682 = 0.682mph


What about switching between metric and imperial units?


Okay, now you know about metric and imperial units, get ready to learn how to convert metric to imperial and imperial to metric.


For more on metric vs imperial click:

What is the metric system?

Metric to imperial conversion

Imperial to metric


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