The imperial measurement system originated from human body parts and varied over time. A cubit was the length from the elbow to the tip of the fingers. An inch was three grains of barley laid end to end. A pound was the weight of a bag of 7,200 grains of barley. Imperial units like feet, yards, miles, ounces, pounds and more were defined, but conversions between units grew increasingly complex over centuries of use.

1. Overview of the
Imperial
Measurement
System

2. Overview of the
Imperial
Measurement
System

3. Overview of the
Imperial
Measurement
System

4. Overview of the
Imperial
Measurement
System

5. In the beginning…

6. …things were measured
in body parts

7. One of the
oldest
known units
is a…

8. CUBIT

9. CUBIT

10. CUBIT
length of an
arm from the
tip of the
fingers to the
elbow

11. Some more…

13. one nail

14. one nail

15. one nail
one digit

16. one nail
one digit

17. one nail
one digit
one span

18. one nail
one digit
one span

19. one nail
one digit
one span
one palm

21. one shaftment

23. one fathom

24. one yard

25. Yard = a
distance from
king’s nose to
the end of his
outstretched
thumb

26. Thanks to
Henry I of
England

27. Thanks to
Henry I of
England

28. One Perch or Rod is…
1

29. One Perch or Rod is…
1 2

30. One Perch or Rod is…
1 2 3 4

31. One Perch or Rod is…
1 2 3 4
5 6 7 8

32. One Perch or Rod is…
1 2 3 4
9 10 11 12
5 6 7 8

33. One Perch or Rod is…
1 2 3 4
9 10 11 12
5 6 7 8
13 14 15 16

34. One Perch or Rod is…
1 2 3 4
9 10 11 12
5 6 7 8
13 14 15 16

35. One Perch or Rod is…
1 2 3 4
9 10 11 12
5 6 7 8
13 14 15

36. One Perch or Rod is…
total length of the left
feet of the first 16
men to leave church on
Sunday morning

37. One Perch or Rod is…
total length of the left
feet of the first 16
men to leave church on
Sunday morning

41. An Inch

42. An Inch

43. An Inch

44. An Inch

45. An Inch
Length of 3
grains of
barley

46. An Inch

47. MORE…

48. MORE…
es m ake a foot
3 inch

49. MORE…
es m ake a foot
3 inch
3 feet make an ulna

50. MORE…
es m ake a foot
3 inch
3 feet make an ulna
5½ ulna m ake a perch

51. MORE…
es m ake a foot
3 inch
3 feet make an ulna
5½ ulna m ake a perch
or a rod

52. MORE…
es m ake a foot
3 inch
3 feet make an ulna
5½ ulna m ake a perch
an area o or a rod
f 40 perch
by 4 perc es
h e s is a n
acre

54. But wait, there is still
MORE…

55. One POUND is a
One pound
weight of a bag
(7,200 grains)
of barley

56. Note: a POUND
Is a unit of
FORCE
not mass

58. A STONE

59. One Stone is
Mass of 14 bags of
barley
(7,200 grains per bag)

61. BUT WAIT….

62. BUT WAIT….
There are also
Troy Pounds

63. A Troy Pound is a
weight of 5,760 grains
of barley

69. Some More Imperial
Conversions

70. Units of Mass

71. Units of Mass
1 stone =

72. Units of Mass
9800 grain
1 stone =

73. Units of Mass
9800 grain
1 stone =
1.75 cloves

74. Units of Mass
9800 grain
1 stone =
1.75 cloves
4083 pennyweights

75. There are

76. There are
s cru ple
in si na
2 0gra

77. There are
s cru ple
in si na
2 0gra
288 grains in a
shilling

78. Units of Volume

79. Units of Volume
1 pony 2 mouthful

80. Units of Volume
1 pony 2 mouthful
1 jack 4 mouthful

81. Units of Volume
1 pony 2 mouthful
1 jack 4 mouthful
1 gill 8 mouthful

82. Units of Volume
1 pony 2 mouthful
1 jack 4 mouthful
1 gill 8 mouthful
1 cup 16 mouthful

83. Units of Volume

84. Units of Volume
1 pint 32 mouthful

85. Units of Volume
1 pint 32 mouthful
1 quart 64 mouthful

86. Units of Volume
1 pint 32 mouthful
1 quart 64 mouthful
1 gallon 256
mouthful

87. Units of Length

88. s e eds = 1 b a r l e y co r n
4 poppy

89. s e eds = 1 b a r l e y co r n
4 poppy
3 barleycorn = 1 inch

90. s e eds = 1 b a r l e y co r n
4 poppy
3 barleycorn = 1 inch
3i nches = 1 palm

91. s e eds = 1 b a r l e y co r n
4 poppy
3 barleycorn = 1 inch
3i nches = 1 palm
2 palms = 1 shaftm
en t

92. s e eds = 1 b a r l e y co r n
4 poppy
3 barleycorn = 1 inch
3i nches = 1 palm
2 palms = 1 shaftm
en t
5 shaft ment = 1 pace

93. s e eds = 1 b a r l e y co r n
4 poppy
3 barleycorn = 1 inch
3i nches = 1 palm
2 palms = 1 shaftm
en t
5 shaft ment = 1 pace
8 paces = 1 rope

94. s e eds = 1 b a r l e y co r n
4 poppy
3 barleycorn = 1 inch
3i nches = 1 palm
2 palms = 1 shaftm
en t
5 shaft ment = 1 pace
8 paces = 1 rope
2 50 ropes = 1 mile

95. Ask me again why we
should use the metric
system