Who can tell me how to convert some units of measurement And please tell me the reason of conversion, such as inch, hectare, square meter, etc I also need China's common conversion unit! I don't often use international ones

Who can tell me how to convert some units of measurement And please tell me the reason of conversion, such as inch, hectare, square meter, etc I also need China's common conversion unit! I don't often use international ones

length
1 inch = 25.4 mm
1 foot = 12 inches = 0.3048 meters
1 yard = 3 feet = 0.9114 meters
1 mile = 1760 yards = 1.609 km
1 nautical mile = 1852 meters
the measure of area
1 sq in = 6.45 sq cm
1 square foot = 144 square inches = 9.29 square decimeters
1 square yard = 9 square feet = 0.836 square meters
1 acre = 4840 square yards = 0.405 hectares
1 square mile = 640 acres = 259 hectares
volume
1 cubic inch = 16.4 cubic centimeter
1 cubic foot = 1728 cubic inches = 0.0283 cubic meters
1 cubic yard = 27 cubic feet = 0.765 cubic meters
volume
British system
1 pint = 20 fl oz = 34.68 Cu in = 0.568 L
1 Quart = 2 pints = 1.136 liters
1 garun = 4 quarts = 4.546 liters
1 peck = 2 garland = 9.092 liters
1 bushel = 4 peck = 36.4 liter
18 bushels = 8 bushels = 2.91 hundred liters
American dry
1 pint = 33.60 Cu in = 0.550 L
1 Quart = 2 pins pints = 1.101 liters
1 peg = 8 quarts Quart = 8.81 L
1 bushel = 4S peck = 35.3l US liquid
1 pint = 16 fl oz = 28.88 Cu in = 0.473 L
1 Quart = 2 pints = 0.946 liters
1 Galen = 4 quarts = 3.785 liters
Changheng
1 grain = 0.065g
1 Dalan = 1.772g
1 oz = 16 DRAM = 28.35 G
1 pound = 16 ounces = 7000 grains = 0.4536 kg
1 stone = 14 pounds = 6.35 kg
1 quarter CWT = 2 stone = 12.70 kg
1 CWT = 4 / 4 CWT = 50.80 kg
1 short ton (US ton) = 2000 lbs = 0.907 MT
1 long ton (British ton) = 20 CWT = 1.016 MT
The conversion relationship between weight and volume of specific consumption tax goods is as follows:
Beer 1 ton = 988 liters yellow rice wine 1 ton = 962 liters
Gasoline 1 ton = 1388l diesel 1 ton = 1176l

For all units of measurement in Chinese and English!

Degree ′ minute ″ second second number Length 1 inch = 25.4 millimeters millimeter foot foot = 12 inches inch = 0.3048 meters meter yard = 3 feet foot = 0

How to convert the unit of length and area in ancient China?
For example, how many centimeters and meters are converted into today's inches, feet and feet? And how many Mu and hectare are are equivalent to?

Degree, that is, length, is closely related to life. It has appeared since the beginning of human beings. From the primitive people's cloth finger was inch, cloth palm was ruler, and elbow was Zhang, to the unified measurement of Qin Shihuang, until the emergence of modern measurement technology, the evolution of ancient degree system reflects the historical changes
summer
1 foot = 10 inches (1 foot = 24.9 cm)
merchant
1 foot = 10 inches, 1 inch = 10 minutes (1 foot = 31.1cm)
week
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 19.9 cm)
Qin Dynasty
1 lead = 10 Zhang, 1 Zhang = 10 feet, 1 foot = 10 inches, 1 inch = 10 minutes (1 foot = 27.7 cm)
Chinese
1 lead = 10 Zhang, 1 Zhang = 10 feet, 1 foot = 10 inches, 1 inch = 10 minutes (1 foot = 27.7 cm)
Xin Mang
1 lead = 10 Zhang, 1 Zhang = 10 feet, 1 foot = 10 inches, 1 inch = 10 minutes (1 foot = 23 cm)
three countries
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 24.1cm)
The Western Jin Dynasty
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 23 cm)
Eastern Jin Dynasty
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 24.5cm)
the Sixteen Kingdoms
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 24.5cm)
The southern and Northern Dynasties
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 24.5 cm; one foot = 29.6 cm)
Sui Dynasty
1 foot = 10 feet, 1 foot = 10 inches, 1 inch = 10 minutes (early stage: 1 foot = 29.6cm; later stage: 1 foot = 23.5cm)
Tang Dynasty;
Five Dynasties
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (small foot: one foot = 31.1 cm; large foot: one foot = 36 cm)
Song Dynasty
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 30.7 cm)
element
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 30.7 cm)
bright
1 foot = 10 feet, 1 foot = 10 inches, 1 inch = 10 minutes (tailoring ruler: 1 foot = 34 cm; floor measuring ruler: 1 foot = 32.7 cm; construction ruler: 1 foot = 31.1 cm)
clear
1 foot = 10 feet, 1 foot = 10 inches, 1 inch = 10 minutes (tailoring ruler: 1 foot = 35.5 cm; floor measuring ruler: 1 foot = 34.5 cm; construction ruler: 1 foot = 32 cm)
modern
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 33.33 cm)
One hectare is equal to 15 mu, one mu is equal to 60 square feet, 15 mu is equal to one hectare, and one mu is about 667 square meters
In the Qin Dynasty, two hundred and forty steps can be used to measure the land area, or from ten years to ten years
What's up? It's very comprehensive!