Help:Convert units

This help page is a how-to guide. It explains concepts or processes used by the Wikipedia community. It is not one of Wikipedia's policies or guidelines, and may reflect varying levels of consensus.

Shortcut H:CONUH:CONU

Template {{convert}} converts a value from one unit of measurement to another. This page documents some features of units, and lists units that are commonly used in conversions.

• Help:Convert • Overview
• Module:Convert/documentation/conversion data • Full list of units
• Help:Convert messages • Error and warning messages

If no output unit is specified, the default output for the input unit will be used. Using defaults provides greater uniformity across articles.

Some options provide text that the template may mistakenly use for the output unit, if none is specified. That can be avoided by providing an empty output unit, as shown in the following examples.

• {{convert|4|ft}} → 4 feet (1.2 m)
• {{convert|4|ft|adj=mid|-long}} → 4-foot (^{[convert: unknown unit]})
• {{convert|4|ft||adj=mid|-long}} → 4-foot-long (1.2 m)

The second of the above examples produces an error because "-long" is interpreted as the name of the output unit. The third example avoids that by specifying an empty output unit, which means "use the default."

The following also works, although it sets the output precision to 0.

• {{convert|4|ft|0|adj=mid|-long}} → 4-foot-long (1 m)

The last example works because "|0" sets the output precision to zero, and convert does not look for an output unit once the precision has been specified because a precision is always given after the output unit, if any.

The standard SI prefixes can applied to the following units.

Some SI prefixes are demonstrated in the following. As a convenience, "micro" can be entered as "u" instead of "μ".

• {{convert|1.23|Gm|angstrom}} → 1.23 gigametres (1.23×10¹⁹ Å)
• {{convert|1.23|Mm|angstrom}} → 1.23 megametres (1.23×10¹⁶ Å)
• {{convert|1.23|Ts|hour}} → 1.23 teraseconds (340,000,000 h)
• {{convert|1.23|nJ|Wh}} → 1.23 nanojoules (3.4×10⁻¹³ Wh)
• {{convert|1.23|μm|in}} → 1.23 micrometres (4.8×10⁻⁵ in)
• {{convert|1.23|um|in}} → 1.23 micrometres (4.8×10⁻⁵ in)
• {{convert|1.23|um|uin|abbr=on}} → 1.23 μm (48 μin)
• {{convert|18|mm|in}} → 18 millimetres (0.71 in)
• {{convert|18|km|mi}} → 18 kilometres (11 mi)

The above demonstrates that "uin" is the unit code for microinch.

An input unit can be converted to any number of output units—the outputs are specified as a "combination" by separating unit codes with a space (" ") or a plus ("+"). Using a space as a separator does not work if any of the unit codes contains a space.

For example, each of the following converts 1.2 km² to acres, square yards, and hectares.

• {{convert|1.2|km2|acre sqyd ha}} → 1.2 square kilometres (300 acres; 1,400,000 sq yd; 120 ha)
• {{convert|1.2|km2|acre+sqyd+ha}} → 1.2 square kilometres (300 acres; 1,400,000 sq yd; 120 ha)

In the following, because "board feet" contains a space, using a space to make a combination fails.

• {{convert|123|cuyd|m3 board feet}} → 123 cubic yards (^{[convert: unknown unit]})
• {{convert|123|cuyd|m3+board feet}} → 123 cubic yards (94 m³; 40,000 board feet)

The following converts a pressure to four output units. The precision is 1 (1 decimal place), and units are abbreviated and linked.

• {{convert|895|hPa|psi inHg atm mbar|1|abbr=on|lk=on}} → 895 hPa (13.0 psi; 26.4 inHg; 0.9 atm; 895.0 mbar)

It is preferable to use "+" to separate output units when the first unit uses engineering notation; that avoids looking up the unit in Module:Convert/extra.

• {{convert|1.2|AU|e6km+e6mi|abbr=on}} → 1.2 AU (180×10^⁶ km; 110×10^⁶ mi)
• {{convert|1.2|AU|e6km+e6mi|abbr=unit}} → 1.2 AU (180 million km; 110 million mi)

Some "standard" combinations have been defined—see the full list of units.

Most units can be combined with a scale factor, for example, e6km represents a million kilometres. The following prefixes may be used; per WP:NUMERAL, values follow the short scale. If lk is on, the numbers are linked as shown below.

• e3 (thousand)
• e6 (million)
• e9 (billion)
• e12 (trillion)
• e15 (quadrillion)

Engineering notation can only be applied to simple units—temperatures, combinations, and some other special units will not work.

Some examples using engineering notation follow.

• {{convert|123.4|e3m2}} → 123.4 thousand square metres (1.328×10^⁶ sq ft)
• {{convert|123.4|e3m2|e6sqft|abbr=off}} → 123.4 thousand square metres (1.328 million square feet)
• {{convert|1.23|e6L}} → 1.23 million litres (320,000 US gal)
• {{convert|1.23|e6L|e3usgal|abbr=off|lk=on|sp=us}} → 1.23 million liters (320 thousand U.S. gallons)
• {{convert|1.23|e9impgal}} → 1.23 billion imperial gallons (5.6 Gl)
• {{convert|1.23|e9impgal|e3usgal|abbr=off|lk=on}} → 1.23 billion imperial gallons (1,480,000 thousand US gallons)
• {{convert|1.23|e12cuft}} → 1.23 trillion cubic feet (35×10^⁹ m³)

Here are the most commonly used units. See below for hands or Mach. For rarer or historic units, see Module:Convert/documentation/conversion data#Conversions.

Examples:

• {{convert|1.5|sqmi|km2}} → 1.5 square miles (3.9 km²)
• {{convert|1.5|sqmi|km2|abbr=off}} → 1.5 square miles (3.9 square kilometres)
• {{convert|1.5|sqmi|km2|abbr=on}} → 1.5 sq mi (3.9 km²)

Examples:

• {{convert|12|mpgus|km/L}} → 12 miles per US gallon (5.1 km/L)
• {{convert|12|mpgus|km/L|abbr=off}} → 12 miles per US gallon (5.1 kilometres per litre)
• {{convert|12|mpgus|km/L|abbr=off|sp=us}} → 12 miles per U.S. gallon (5.1 kilometers per liter)
• {{convert|12|mpgus|km/L|abbr=on}} → 12 mpg_‑US (5.1 km/L)

Examples:

• {{convert|123|cm|in}} → 123 centimetres (48 in)
• {{convert|123|cm|in|abbr=off|sp=us}} → 123 centimeters (48 inches)
• {{convert|123|cm|in|abbr=on}} → 123 cm (48 in)

Examples:

• {{convert|72.3|kg|lb}} → 72.3 kilograms (159 lb)
• {{convert|72.3|kg|lb|abbr=off}} → 72.3 kilograms (159 pounds)
• {{convert|72.3|kg|lb|abbr=on}} → 72.3 kg (159 lb)

Examples:

• {{convert|28|psi|Pa}} → 28 pounds per square inch (190,000 Pa)
• {{convert|28|psi|Pa|abbr=off}} → 28 pounds per square inch (190,000 pascals)
• {{convert|28|psi|Pa|abbr=on}} → 28 psi (190,000 Pa)

Examples:

• {{convert|60|mph|km/h}} → 60 miles per hour (97 km/h)
• {{convert|60|mph|km/h|abbr=off}} → 60 miles per hour (97 kilometres per hour)
• {{convert|60|mph|km/h|abbr=on}} → 60 mph (97 km/h)

Examples:

• {{convert|100|C|F}} → 100 °C (212 °F)
• {{convert|100|C|F|abbr=off}} → 100 degrees Celsius (212 degrees Fahrenheit)
• {{convert|100|C-change|F-change}} → 100 °C (180 °F)
• {{convert|100|C-change|F-change|abbr=out}} → 100 degrees Celsius change (180 °F)

Examples:

• {{convert|12.5|Nm|lb.in}} → 12.5 newton-metres (111 lb⋅in)
• {{convert|12.5|Nm|lb.in|abbr=off}} → 12.5 newton-metres (111 pound force-inchs)
• {{convert|12.5|Nm|lb.in|abbr=on|lk=on}} → 12.5 N⋅m (111 lb⋅in)

Examples:

• {{convert|125|cuin|l}} → 125 cubic inches (2.05 L)
• {{convert|125|cuin|l|abbr=off}} → 125 cubic inches (2.05 litres)
• {{convert|125|cuin|l|abbr=on}} → 125 cu in (2.05 L)

A hand is a unit of length used to measure the height of horses. One hand is four inches, and a value of 12.3 hands represents 12 hands + 3 inches (51 inches).

• By default, the unit is shown as a linked name (hands).
• The hands unit can be abbreviated to "h" or to "hh"; by default, abbreviations are not linked.

  {{convert|27|in|hand}} → 27 inches (6.3 hands)

  {{convert|27|in|hand|lk=off}} → 27 inches (6.3 hands)

  {{convert|27|in|hand|abbr=h}} → 27 in (6.3 h)

  {{convert|27|in|hand|abbr=hh}} → 27 in (6.3 hh)

  {{convert|27|in|hand|abbr=hh|lk=out}} → 27 in (6.3 hh)

• The hands value has at most one digit after the decimal mark, and has an optional fraction.
• A precision of 2 assumes |frac=2 (round to nearest 1⁄2 inch).
• A precision of 3 or more assumes |frac=4 (round to nearest 1⁄4 inch).
• If ever needed, |frac=8 can be used to round to the nearest 1⁄8 inch.

  {{convert|27.63|in|hand}} → 27.63 inches (7.0 hands)

  {{convert|27.63|in|hand|0}} → 27.63 inches (7 hands)

  {{convert|27.63|in|hand|1}} → 27.63 inches (7.0 hands)

  {{convert|27.63|in|hand|2}} → 27.63 inches (6.3+1⁄2 hands)

  {{convert|27.63|in|hand|3}} → 27.63 inches (6.3+3⁄4 hands)

  {{convert|27.63|in|hand|frac=8}} → 27.63 inches (6.3+5⁄8 hands)

  {{convert|28.5|in|hand|2}} → 28.5 inches (7.0+1⁄2 hands)

  {{convert|28.5|in|hand|3}} → 28.5 inches (7.0+1⁄2 hands)

• When using "hand in" to convert to hands and inches, the rounded hands and inches values are equivalent, and use the same fraction, if any.
• Special rounding of the inches value only occurs when "hand in" is the output. For example, if the output is "in hand", the inches value is rounded independently from the hands value.

  {{convert|156|cm|hand in}} → 156 centimetres (15.1 hands; 61 in)

  {{convert|156|cm|hand in|2}} → 156 centimetres (15.1+1⁄2 hands; 61+1⁄2 in)

  {{convert|156|cm|in hand}} → 156 centimetres (61 in; 15.1 hands)

  {{convert|156|cm|in hand|2}} → 156 centimetres (61.42 in; 15.1+1⁄2 hands)

  {{convert|156|cm|hand in|abbr=out}} → 156 centimetres (15.1 h; 61 in)

  {{convert|156|cm|hand in|abbr=h}} → 156 cm (15.1 h; 61 in)

  {{convert|156|cm|hand in|abbr=hh}} → 156 cm (15.1 hh; 61 in)

• A range of values can be indicated with "-" (hyphen) or "to". When a dash is displayed by convert, it is always an en dash.
• Alternatively, "and" and "or" can be used.

  {{convert|137|-|156|cm|hand in}} → 137–156 centimetres (13.2–15.1 hands; 54–61 in)

  {{convert|137|-|156|cm|hand in|2}} → 137–156 centimetres (13.2–15.1+1⁄2 hands; 54–61+1⁄2 in)

  {{convert|137|-|156|cm|hand in|abbr=in}} → 137–156 cm (13.2–15.1 hands; 54–61 inches)

  {{convert|137|-|156|cm|hand in|abbr=h}} → 137–156 cm (13.2–15.1 h; 54–61 in)

  {{convert|137|-|156|cm|hand in|abbr=on}} → 137–156 cm (13.2–15.1 h; 54–61 in)

  {{convert|15000|-|20000|usgal|impgal L|abbr=on}} → 15,000–20,000 US gal (12,000–17,000 imp gal; 57,000–76,000 L)

  {{convert|137|and|156|cm|hand in|abbr=on}} → 137 and 156 cm (13.2 and 15.1 h; 54 and 61 in)

  {{convert|137|or|156|cm|hand in|abbr=on}} → 137 or 156 cm (13.2 or 15.1 h; 54 or 61 in)

• The following examples illustrate various combinations of options.

  {{convert|57|in|hand}} → 57 inches (14.1 hands)

  {{convert|2|m|hand}} → 2 metres (19.3 hands)

  {{convert|137|cm|hand|2}} → 137 centimetres (13.2 hands)

  {{convert|137|cm|hand|2|sp=us}} → 137 centimeters (13.2 hands)

  {{convert|14.1|hand|in}} → 14.1 hands (57 inches)

  {{convert|14.1|hand|cm}} → 14.1 hands (145 cm)

  {{convert|14.1|hand|in cm}} → 14.1 hands (57 inches; 145 cm)

  {{convert|14.1|hand|cm in}} → 14.1 hands (145 cm; 57 inches)

  {{convert|14.1|-|14.3|hand|cm}} → 14.1–14.3 hands (145–150 cm)

  {{convert|14.1|-|14.3|hand|in cm}} → 14.1–14.3 hands (57–59 inches; 145–150 cm)

  {{convert|50|-|57|in|hand}} → 50–57 inches (12.2–14.1 hands)

  {{convert|2|-|3|m|hand}} → 2–3 metres (19.3–29.2 hands)

  {{convert|57|or|59|in|hand|abbr=on}} → 57 or 59 in (14.1 or 14.3 h)

  {{convert|137|-|139|cm|hand|lk=on}} → 137–139 centimetres (13.2–13.3 hands)

  {{convert|137|and|162|cm|hand|0|abbr=in|lk=in}} → 137 and 162 cm (13 and 16 hands)

  {{convert|137|and|162|cm|hand in}} → 137 and 162 centimetres (13.2 and 16.0 hands; 54 and 64 in)

  {{convert|9.2|hand}} → 9.2 hands (38 inches; 97 cm)

  {{convert|9.2|hand|lk=off}} → 9.2 hands (38 inches; 97 cm)

  {{convert|9.2|hand|abbr=h}} → 9.2 h (38 in; 97 cm)

  {{convert|9.2|hand|abbr=h|lk=in}} → 9.2 h (38 in; 97 cm)

  {{convert|9.2|hand|abbr=hh|lk=in}} → 9.2 hh (38 in; 97 cm)

  {{convert|9.2+1/2|hand}} → 9.2+1⁄2 hands (38.5 inches; 98 cm)

  {{convert|9.2+3/4|hand}} → 9.2+3⁄4 hands (38.75 inches; 98 cm)

  {{convert|9.2+3/4|hand|abbr=h}} → 9.2+3⁄4 h (38.75 in; 98 cm)

  {{convert|9.2+3/4|hand|cm in}} → 9.2+3⁄4 hands (98 cm; 38.75 inches)

  {{convert|9.2+3/4|hand|cm in|abbr=out}} → 9.2+3⁄4 hands (98 cm; 38.75 in)

  {{convert|9.2+3/4|hand|cm in|abbr=on}} → 9.2+3⁄4 h (98 cm; 38.75 in)

  {{convert|9.2+3/4|hand|in}} → 9.2+3⁄4 hands (38.75 inches)

  {{convert|9.2+3/4|hand|in|abbr=out}} → 9.2+3⁄4 hands (38.75 in)

  {{convert|9.2+3/4|hand|in|abbr=on}} → 9.2+3⁄4 h (38.75 in)

  {{convert|15.1|-|16.3|hand}} → 15.1–16.3 hands (61–67 inches; 155–170 cm)

  {{convert|14.2|to|16.1|hand}} → 14.2 to 16.1 hands (58 to 65 inches; 147 to 165 cm)

Conversion of the Mach unit of speed depends on the altitude at which the speed is measured. That altitude should be specified either in feet (for example, |altitude_ft=10,000) or in metres (for example, |altitude_m=3,749). The altitude cannot be determined accurately and only a whole number is accepted.

Examples:

• {{convert|1.6|Mach|altitude_ft=20,000|mph}} → Mach 1.6 (1,130 mph)
• {{convert|1.6|Mach|altitude_m=6,096|mph}} → Mach 1.6 (1,130 mph)
• {{cvt|1130|mph|Mach|altitude_m=6,096|lk=out}} → 1,130 mph (Mach 1.6)
• {{convert|5|-|7|Mach|altitude_ft=34,500}} → Mach 5 – Mach 7 (5,400–7,500 km/h; 3,300–4,700 mph)