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How Do You Convert Metric to Imperial?

When you convert metric units to imperial units, you need to multiply each unit by a conversion factor. This entry will give you an overview of which conversion factor to use and which imperial unit it will produce.

Length

For length you usually convert centimeters to inches or feet, decimeters to feet, meters to feet or yards and kilometers to miles.


Metric Unit	Conversion Factor	Imperial Unit

$1$ cm	$\cdot 0.3937$	$0.3937 in \approx 0.4 in$

$1$ dm	$\cdot 0.3280$	$0.3280 ft \approx 0.33 ft$

$1$ m	$\cdot 1.0936$	$1.0936 yd \approx 1.1 yd$

$1$ km	$\cdot 0.6214$	$0.6214 mi \approx 0.6 mi$

Example 1

A European soccer field is exactly 105 meters. How long is that in yards?

You find the conversion factor from the table above to be $1.0936$ :

105 m \cdot 1.0936 \approx 114.8 yd .

Area

For area you usually convert square centimeters to square inches, square decimeters to square feet, square meters to square yards or acres and square kilometers to square miles.


Metric Unit	Conversion Factor	Imperial Unit

$1$ cm²	$\cdot 0.1550$	$0.1550 {in}^{2} \approx 0.16 {in}^{2}$

$1$ dm²	$\cdot 929$	$929 {ft}^{2} \approx 0.09 {ft}^{2}$

$1$ m²	$\cdot 1.1960$	$1.1960 {yd}^{2} \approx 1.2 {yd}^{2}$

$1$ km²	$\cdot 247.1$	$247.1 acre \approx 250 acre$

$1$ km²	$\cdot 0.3861$	$0.3861 {mi}^{2} \approx 0.4 {mi}^{2}$

Example 2

Your farm is 175 meters long and 155 meters wide. How many acres is that?

Square meters:

175 m \cdot 155 m = 27 125 m^{2} .

The table converts from km² to acre, so you need to convert to km² first:

\frac{27 125 m^{2}}{1 000 000} \approx 0.027 13 {km}^{2} .

Then you use the table above to convert to acres:

0.027 13 {km}^{2} \cdot 247.1 \approx 6.7 acres .

Volume

For volume you usually convert milliliters to fluid ounces, deciliters to cups and liters to pints or gallons. How much a cup contains varies from country to country. In this entry we use the US cup.


Metric Unit	Conversion Factor	Imperial Unit

$1$ mL	$\cdot 0.0338$	$0.0338 fl oz \approx 0.03 fl oz$

$1$ dL	$\cdot 3.381$	$3.381 fl oz \approx 3.4 fl oz$

$1$ dL	$\cdot 0.4227$	$0.4227 cup \approx 0.4 cup$

$1$ L	$\cdot 0.264 17$	$0.264 17 gal \approx 0.3 gal$

Example 3

You visit Australia and discover that a single shot glass there has a volume of $30 mL$ . How much is that in fluid ounces?

You need to find out how many fluid ounces $30$ mL is:

30 mL \cdot 0.0338 \approx 1.014 fl oz \approx 1 fl oz .

Seems like one fluid ounce is one shot.

Weight

Grams are usually converted to ounces, kilograms to pounds and metric tonne to ton.


Metric Unit	Conversion Factor	Imperial Unit

$1$ g	$\cdot 0.035 27$	$0.035 27 oz \approx 0.04 oz$

$1$ kg	$\cdot 2.2056$	$2.2056 lb \approx 2.2 lb$

$1$ tonne	$\cdot 1.1023$	$1.1023 ton \approx 1.1 ton$

Example 4

You visit a fitness center in the USA. You know you can safely bench press $50 kg$ , but how much is that in pounds?

The table above gives

50 kg \cdot 2.2056 \approx 110.3 lb .

So, don’t go over $110$ lb unless you have a spotter.

Mass Density

Since density consist of two units, you can convert each of them separately and then combine them. Density in metric is often given by g/cm³ while imperial uses lb/ft³. You can convert g/cm³ to lb/ft³ by first converting grams to pounds and then centimeters to feet. One centimeter is $0.0328$ feet, so one cubed centimeter is $0.032 8^{3} = 0.000 035 3 {ft}^{3}$ : $\begin{array}{l} 1 g & = 0.002 205 lb \\ 1 {cm}^{3} & = 0.000 035 3 {ft}^{3} \\ 1 {g/cm}^{3} & = \frac{0.002 205 lb}{0.000 035 3 {ft}^{3}} \approx 62.5 {lb/ft}^{3} . \end{array}$

Rule

You convert from g/cm³ to lb/ft³ by multiplying g/cm³ with $62.5$ .

Temperature

The US uses Fahrenheit while most other countries uses Celsius. Unlike most other units, you cannot multiply Celsius with a conversion factor to get Fahrenheit. Instead, you have to use this simple formula:

Formula

°C is temperature measured in Celsius and °F is temperature measured in Fahrenheit.

°F = 1.8 \cdot °C + 32

Example 5

On a cold winter’s day, it’s $- 28 °C$ outside. What is that in Fahrenheit?

You use the above formula:

1.8 \cdot (- 28 °C) + 32 = - 50.4 + 32 = - 18.4 °F .

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How Do You Convert Imperial to Metric?

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