# Help:Convert messages

This page describes the error and warning messages reported by Module:Convert if a problem is detected while using {{convert}} to convert a value from one unit of measurement to another.

If a problem cannot readily be resolved, please report it at one of the following.

## Error and warning messages

### Needs a number

Mouseover the message to see further information.[a]

• `{{convert|123|m|ft}}` → 123 metres (404 ft)
• `{{convert||m|ft}}`[convert: needs a number]

An input number is required. In the first example above, the input number is `123`.

Pages with this error are automatically placed in Category:Convert errors.[b]

### Needs another number

Mouseover the message to see further information.[a]

The first input number was specified, but the range used requires another number.

Pages with this error are automatically placed in Category:Convert errors.[b]

### Invalid number

Mouseover the message to see further information.[a]

• `{{convert|1|km|ft}}` → 1 kilometre (3,300 ft)
• `{{convert|km|ft}}`[convert: invalid number]

A number to be converted can be entered as in these examples: `1.23` or `1,234` or `-0.9`.

Fractions are entered as in these examples: `1+2/3` (1+23) or `-1-2/3` (−1+23) or `2/3` (23).

Pages with this error are automatically placed in Category:Convert errors.[b]

### Number overflow

Mouseover the message to see further information.[a]

• `{{convert|1e290|m|ft}}` → 1×10290 metres (3.3×10290 ft)
• `{{convert|1e310|m|ft}}`[convert: number overflow]

This error occurs if a number exceeds the range of values available for calculations. The number 1e290 means 1×10290.

Pages with this error are automatically placed in Category:Convert errors.[b]

### Invalid precision

Mouseover the message to see further information.[a]

• `{{convert|21455|acre|ha|2}}` → 21,455 acres (8,682.53 ha)
• `{{convert|21455|acre|ha|-2}}` → 21,455 acres (8,700 ha)
• `{{convert|21455|acre|ha|2.5}}` → 21,455 acres (8,683 ha)[convert: invalid precision]

A precision value is entered after the conversion information. For example, `|2` gives a result that is rounded to two decimal places, while `|-2` rounds to the nearest 100 so that two zeroes occur at the end of the number. This message will only appear if warnings have been enabled.

Pages with this error are automatically placed in Category:Convert errors.[b]

### Precision too large

Mouseover the message to see further information.[a]

Generally there is no reason to use a precision of more than a few decimal places, however, larger values may be used. The error shown occurs if the requested precision is higher than the maximum supported by the server.

A negative precision rounds to the nearest 10 (parameter `|-1`), or nearest 100 (`|-2`), or nearest 1000 (`|-3`), etc. A large negative precision produces a zero output.

• `{{convert|123|m|ft|-2}}` → 123 metres (400 ft)
• `{{convert|123|m|ft|-200}}` → 123 metres (0 ft)

Using a very small input value can cause the default precision to exceed the limit (`1.234e-200` is 1.234×10−200). For such very small values, it is better to use the `|sigfig=` option.

• `{{convert|1.234|m|ft}}` → 1.234 metres (4.05 ft)
• `{{convert|1.234e-200|m|ft}}`[convert: precision too large]
• `{{convert|1.234e-200|m|ft|sigfig=3}}` → 1.234×10−200 metres (4.05×10−200 ft)

Pages with this error are automatically placed in Category:Convert errors.[b]

### Invalid altitude

Mouseover the message to see further information.[a]

• `{{convert|1.9|Mach|km/h|altitude_ft=5200}}` → Mach 1.9 (2,290 km/h)
• `{{convert|1.9|Mach|km/h|altitude_ft=5200.5}}` → Mach 1.9 (2,330 km/h)*
• `{{convert|1.9|Mach|km/h|altitude_ft=on}}` → Mach 1.9 (2,330 km/h)*

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.

Pages with this error are automatically placed in Category:Convert errors.[b]

### Invalid fraction

Mouseover the message to see further information.[a]

• `{{convert|12.31|m|ftin|frac=8}}`12.31 metres (40 ft 4+58 in)
• `{{convert|12.31|m|ftin|frac=1}}` → 12.31 metres (40 ft 5 in)*
• `{{convert/warning|12.31|m|ftin|frac=on}}` → 12.31 metres (40 ft 5 in)[convert: invalid fraction]

A fraction denominator can be specified to display results with a fraction where appropriate. For example, `|frac=8` specifies that the value should be rounded to the nearest eighth, and that a fraction should be included if necessary. A fraction denominator must be a whole number with value 2 or more. This message will only appear if warnings have been enabled.

Pages with this error are automatically placed in Category:Convert errors.[b]

### Invalid sigfig

Mouseover the message to see further information.[a]

• `{{convert|1234|ft|m|sigfig=2}}` → 1,234 feet (380 m)
• `{{convert|1234|ft|m|sigfig=0}}` → 1,234 feet (376 m)[convert: invalid sigfig]
• `{{convert|1234|ft|m|sigfig=2.5}}` → 1,234 feet (376 m)[convert: invalid sigfig]

The number of significant figures in the result can be specified. For example, `|sigfig=2` requests two significant figures. The number of significant figures must be a whole number with value 1 or more. This message will only appear if warnings have been enabled.

Pages with this error are automatically placed in Category:Convert errors.[b]

### Deprecated option

Mouseover the asterisk after the convert result to see further information.[a]

• `{{convert|123|m|ft|sortable=on}}`123 metres (404 ft)
• `{{convert|123|m|ft|sortable=out}}` → 123 metres (404 ft)*

The option `|sortable=on` outputs a hidden sort key for use in a sortable table. The option `|sortable=out` is now the same as `|sortable=on`, and the latter should be used. See deprecated options for information regarding which options should be used to replace those that are being phased out.

Pages with this error are automatically placed in Category:Convert errors.[b]

### Empty option

Mouseover the message to see further information.[a]

• `{{convert|123|m|ft|sp=us}}` → 123 meters (404 ft)
• `{{convert|123|m|ft|sp=}}` → 123 metres (404 ft)[convert: empty option]

The option `|sp=us` specifies that US spelling should be used ("meters" instead of "metres"). However, `|sp=` has no effect as no value is specified. This message will only appear if all warnings have been enabled.

Pages with this error are automatically placed in Category:Convert errors.[b]

### Invalid option

Mouseover the message to see further information.[a]

• `{{convert|123|m|ft|abbr=off}}` → 123 metres (404 feet)
• `{{convert|123|m|ft|abr=off}}` → 123 metres (404 ft)[convert: invalid option]

The option `|abbr=off` specifies that abbreviations are off, that is, unit names will be used instead of symbols. By contrast, `|abr=off` is ignored because "abr" is not the name of an option.

• `{{convert|8.5|m|in|abbr=off}}` → 8.5 metres (330 inches)
• `{{convert|8.5|m|in|abbr=off|28}}` → 8.5 metres (334.64566929133 inches)
• `{{convert|8.5|m|in|abbr=off|in}}` → 8.5 metres (330 inches)[convert: invalid option]
• `{{convert|8.5|m|28|in|abbr=off}}` → 8.5 metres (27.887139107611 feet)[convert: invalid option]

The option `|28`, which should be placed after all the unit options, specifies that 8.5 metres is converted to inches with 28 significant figures. By contrast, `|28``|in` and `|in``|abbr=off``|in` are ignored because `|28` is followed by a unit, and `|in` is not the name of a formatting option.

This message will only appear if warnings have been enabled. Pages with this error are automatically placed in Category:Convert errors.[b]

### Needs unit name

Mouseover the message to see further information.[a]

A unit code must be specified following the input number or numbers.

Pages with this error are automatically placed in Category:Convert errors.[b]

### Unknown unit

Mouseover the message to see further information.[a]

Each unit code must exactly match a known unit, case sensitive. A simplified list of unit codes is at Help:Convert units, and all available unit codes are here.

Pages with this error are automatically placed in Category:Convert errors.[b]

### Unit mismatch

Mouseover the message to see further information.[a]

• `{{convert|123|psi|Pa}}` → 123 pounds per square inch (850,000 Pa)
• `{{convert|123|psi|ha}}` → 123 pounds per square inch ([convert: unit mismatch])

It is only possible to convert between units that have the same type. For example, `psi` and `Pa` are each of type "pressure" so a `psi` value can be converted to `Pa`. However, a `psi` value cannot be converted to a unit of a different type, such as `ha` (hectare) which has type "area".

Pages with this error are automatically placed in Category:Convert errors.[b]

### Ambiguous unit

Mouseover the message to see further information.[a]

• `{{convert|21|mpgus|L/km}}` → 21 miles per US gallon (0.11 L/km)
• `{{convert|21|mpg|L/km}}` → 21 mpg[convert: ambiguous unit]
• `{{convert|21|USpt|L}}` → 21 US pints (9.9 L)
• `{{convert|21|pt|L}}` → 21 pt[convert: ambiguous unit]

Some unit codes are not supported; using them results in an message indicating that a different unit code should be chosen.

Pages with this error are automatically placed in Category:Convert errors.[b]

### Unit invalid here

Mouseover the message to see further information.[a]

• `{{convert|123|K|C F}}` → 123 K (−150 °C; −238 °F)
• `{{convert|123|C F|K}}` → 123 C F[convert: unknown unit]
• `{{convert|12345|ft|mi km}}` → 12,345 feet (2.3381 mi; 3.763 km)
• `{{convert|12345|ft|yd+mi+km}}` → 12,345 feet (4,115 yd; 2.3381 mi; 3.763 km)
• `{{convert|12345|ft|yd+mi km}}` → 12,345 feet ([convert: unknown unit])

Some units can only be used as outputs. For example "`C F`" displays a temperature in Celsius and Fahrenheit. Such a unit cannot be used with an input value, because, for example, there is no such temperature as "`123 C F`". Some output combinations are predefined—"`C F`" is one example, and "`mi km`" (miles and kilometres) is another. It is also possible to construct an output combination by joining unit codes with "`+`". However, individual units have to be specified, and an output combination cannot be used.

Pages with this error are automatically placed in Category:Convert errors.[b]

### Wikidata problem

Mouseover the message to see further information.[a]

An unexpected error occurred while attempting to use the Wikidata modules to read property or item information. This error should not occur; the above is a simulation of what would be displayed if, for example, the Wikidata modules were not available, or if they contained an error.

Pages with this error are automatically placed in Category:Convert errors.[b]

### Invalid input

Mouseover the message to see further information.[a]

Convert is configured to display any input text without error if a conversion fails, so this error should not occur. The above is a simulation of what would be displayed if convert were configured to show problems when a conversion was not possible.

The following examples use the `input` parameter. The unit `mV` is known to convert, but since no useful conversion is possible, there is no output. There is no `boxes` unit, so the input is displayed as given. The final example follows the same rule because `P123.` is not a valid property identifier.

• `{{convert|input=12 mV}}` → 12 millivolts
• `{{convert|input=12 mV|abbr=on}}` → 12 mV
• `{{convert|input=12 boxes}}` → 12 boxes
• `{{convert|input=P123.}}` → P123.

Pages with this error are automatically placed in Category:Convert errors.[b]