Blog about English
Expressing length, weight, distance, temperature, volume and other measurements.
English expresses measurements using a number followed by a unit and can describe exact, approximate, comparative, and proportional quantities.
Examples include two metres, five kilograms, three litres, and twenty degrees.
A measurement expression normally uses a singular unit after one or a quantity grammatically treated as one unit.
For example, one metre, one kilogram, and one hour.
A measurement expression normally uses a plural unit after numbers greater than one.
For example, two metres, five kilograms, and ten hours.
A number and unit used before another noun as a compound adjective normally use a singular unit.
For example, a two-metre wall, a five-kilometre walk, and a ten-year-old child.
Number-unit combinations functioning as compound modifiers before nouns are commonly hyphenated.
For example, a three-year-old child and a twenty-kilometre journey.
When a measurement follows the noun or functions independently, the unit normally takes the appropriate plural form.
For example, The wall is two metres high and The journey is five kilometres.
Measurements of physical dimensions can be expressed with nouns such as metre, centimetre, foot, inch, kilometre, and mile.
For example, The table is two metres long and The room is five metres wide.
Adjectives such as long, wide, high, and tall describe different types of physical dimensions.
For example, The road is ten kilometres long, The wall is three metres high, and The building is very tall.
Deep describes vertical distance into a space or substance, while thick describes the distance between opposite surfaces of a solid layer.
For example, The pool is two metres deep and The wall is twenty centimetres thick.
Weight and mass can be expressed with units such as kilogram, gram, pound, and ounce.
For example, The package weighs five kilograms.
Weigh can be used as a verb followed by a measurement or used with how much to ask about mass.
For example, The box weighs ten kilograms and How much does it weigh?
Height can be expressed with a measurement noun or with an adjective plus measurement.
For example, The building has a height of 100 metres and The building is 100 metres high.
Age can be expressed with a number of years or an age compound.
For example, She is ten years old and a ten-year-old child.
When years functions as part of the predicate expressing age, it normally appears in the plural, while the corresponding compound modifier uses singular year.
For example, He is ten years old but He is a ten-year-old boy.
Distance can be expressed using units such as metre, kilometre, mile, foot, and inch.
For example, The station is two kilometres away.
Away expresses distance from a reference point, commonly after a measurement.
For example, The station is five kilometres away.
Temperature is commonly expressed with degrees followed by a temperature scale or by the temperature value alone when context is clear.
For example, twenty degrees Celsius and It is twenty degrees outside.
English uses degrees Celsius and degrees Fahrenheit to identify temperature scales explicitly.
For example, 20°C is twenty degrees Celsius and 68°F is sixty-eight degrees Fahrenheit.
Negative and positive temperatures can be described relative to zero.
For example, five degrees below zero and ten degrees above zero.
Volume can be expressed with units such as litre, millilitre, gallon, and pint.
For example, two litres of water and 500 millilitres of milk.
Area is commonly expressed with square units.
For example, fifty square metres and ten square kilometres.
Square units measure area, while cubic units measure volume.
For example, square metres measure surface area and cubic metres measure volume.
Per expresses a rate calculated relative to another unit.
For example, 60 kilometres per hour, five dollars per kilogram, and twice per day.
Per cent describes a proportion out of one hundred, while percentage is the corresponding noun.
For example, ten percent of the population and What percentage of users responded?
Words such as about, around, approximately, nearly, and roughly can indicate that a measurement is not exact.
For example, about five metres, roughly ten kilograms, and approximately two hours.
Nearly and almost indicate that a quantity or measurement is close to but does not reach a specified value.
For example, nearly two metres tall and almost five kilometres away.
More than, less than, over, and under can express approximate or bounded measurements.
For example, more than two metres, under five kilograms, and over ten kilometres.
As much as is used with uncountable quantities, while as many as is used with countable plural quantities.
For example, as much as ten litres and as many as one hundred people.
Up to indicates a maximum quantity, distance, duration, or limit.
For example, up to ten people, up to five kilometres, and up to two hours.
A total of emphasizes the complete numerical quantity of something.
For example, A total of 500 people attended the event.
An average of introduces a mean quantity calculated across a set of measurements or observations.
For example, an average of 20 kilometres per day.
Maximum of and minimum of express upper and lower numerical limits.
For example, a maximum of 100 people and a minimum of two hours.
Measurements can be expressed as ranges using from ... to, between ... and, or numerical range punctuation.
For example, from five to ten metres and between 20 and 30 kilograms.
Common measurement units have standard written abbreviations, especially in technical, scientific, and tabular contexts.
For example, km, kg, cm, mL, L, and °C.
Use singular or plural units according to their grammatical position, choose the correct measurement unit, and distinguish exact quantities from approximate ranges.
Common mistakes include using plural units in compound modifiers, confusing metres with square metres, saying ten year old without the correct compound structure, and confusing per-unit rates with total quantities.