Metric yardstick

This article gives some rough rules of thumb for comprehending the metric system in terms of everyday life.

Conversion hints

For users of the U.S. Customary system (often referred to as the 'English' system although the UK is now metric) there are a few simple equivalents and approximate conversion factors that help in learning to be comfortable with the metric system (for exact conversion factors click on the individual unit links)

Near equivalents

The following units are the same within a few percent. The slightly larger unit is listed first
* 1 meter ≈ 1 yard
* 1 liter ≈ 1 quart
* 1 long ton ≈ 1 metric tonne
* 1 BTU ≈ 1 kilojoule

Approximate conversion factors

Length

* 1 mile ≈ 1.6 km
* 1 nautical mile = 1852 m
* 1 meter ≈ 1.1 yard ≈ 3.28 ft
* 1 yard ≈ 0.9 meters
* 1 foot = 0.3048 m, very roughly 1/3 of a meter; 10 ft = 3.048 m
* 1 inch ≈ 25 mm, 4 inches ≈ 10 cm
* 1 cm ≈ 3/8in.

urface

* 1 acre ≈ 4000 square meters ≈ 0.4 hectare

Mass

* 1 kilogram ≈ 2.2 lb
* 1 ounce ≈ 28 grams
* 2 pounds ≈ 1 kg: 2 lb ≈ 900 grams

Volume

* 1 liter ≈ 1.06 quart
* 1 US cup ≈ 240 ml
* 1 teaspoon = 5 ml

Metric yardsticks based on everyday objects

Length

* One meter equals roughly one (longish) step of a tall adult man.
* One kilometer equals ten minutes' walk.
* Most people have at least one fingernail whose width is roughly 1 cm. fact|date=August 2008
* The cubit arm (forearm from elbow to fingertips) is roughly 50 cm. This is known as "metric cubit" and has been used in some countries.
* The width of man's hand is about one decimeter or 10 cm. That is almost the same as the old English unit "hand".
* Compact discs and DVDs are exactly 12 cm in diameter
* The side of a matchbox is 5 cm.
* The length of a two-second pendulum is approximately one meter.

Area

* A large soccer field has an area of one hectare (10,000 square meters).
* The area covered by a large umbrella is roughly one square meter.

Volume

* A cube of one hand (1 decimeter) per side is equal to one liter.
* A drop of water (or water-based solution, like milk, tears, etc.) is very close to 0.05 milliliters. 20 drops make one milliliter. This is an approximation used in chemical engineering.Fact|date=May 2008
* Both the British and American pints are close to 1/2 L, sometimes called the "metric pint".
* Soft drinks are sold in 1, 1.5, 2 and 3 liter bottles.

Cooks beware - Cup sizes differ widely.

Mass

* One milliliter (1 ml) of water is one gram (1 g), and therefore 1000 milliliters of water (1 L) is 1 kilogram (kg).
* 1000 liters of water (a cubic meter - 1 m³) is 1 tonne (1 t = 1000 kg).
* One tonne is roughly the mass of an economy motor car.
* One U.S. "nickel" (5 cent coin) has a mass of 5 g.
* One litre of a soft drink has a mass of roughly 1 kg.

Force

* A small apple on Earth exerts a force due to gravity of about one newton (N). (Remember Newton's apple)
* One kilogram at the Earth's surface exerts a force due to gravity very close to 10 N.
* One newton-meter torque is roughly the increase in torque by adding a small apple to the end of an outstretched walking stick.

Pressure

* Normal air pressure at sea-level is around 100 kilopascals. It equals approximately 1 kgf/cm²
* Every ten metres' depth of seawater exerts about one bar or 100 kPa or 1 kg/cm^{2 of additional pressure.}

Temperature

* For Celsius temperatures
** 30 is hot
** 20 is nice
** 10 is chilly
** 0 is ice.
* The USMA (United States Metrication Association) promotes the following jingle to spread awareness of Celsius: "0 is cold, 10 is not, 20 is warm, and 30 is hot"
* Normal room temperature is roughly 22 °C
* Normal human body temperature is 37 °C (the value 98.6 °F Americans learn is simply the exact conversion of 37 °C; bodies are not that precise)
* Pure water boils at 100 °C and freezes at 0 °C at sea level.
* An outside temperature of 300 kelvins (273 + 27 °C) means bikini weather.

Celsius landmarks

The table below lists easy to remember or particularly important Celsius temperatures.

ee also

*Metrication
*Approximate conversion of units

External links

* [http://www.unitconversion.org/ Unit converter]