Excel CONVERT Function
last modified October 5, 2026
The CONVERT function converts a number from one measurement system
to another. It handles distance, area, volume, mass, time, pressure, force,
energy, power, magnetism, temperature, speed, and information units. This
tutorial provides a comprehensive guide to using the CONVERT
function with detailed examples. You'll learn the syntax, the supported unit
codes, and the mistakes that produce errors.
CONVERT Function Basics
The CONVERT function changes a measurement from one unit to
another. Every conversion stays inside a single measurement category: distance
converts to distance, mass to mass, and so on. Mixing categories returns an
error. The syntax requires three arguments.
| Component | Description |
|---|---|
| Function Name | CONVERT |
| Syntax | =CONVERT(number, from_unit, to_unit) |
| Arguments | Number to convert, original unit, target unit |
| Return Value | Converted measurement in new units |
This table breaks down the essential components of the CONVERT
function. The function requires a numeric value and two unit codes supplied as
text strings.
| Argument | Meaning |
|---|---|
| number | The value to convert. It can be a literal, a cell reference, or an
expression that returns a number. Text that cannot be read as a number
produces a #VALUE! error. |
| from_unit | The unit of number, written as a case-sensitive text code
such as "m", "lbm", or "C". |
| to_unit | The unit of the result, written in the same style. It must belong to
the same measurement category as from_unit. |
Both unit arguments must be enclosed in quotation marks. If a unit does not
exist, or if the two units belong to different categories, the function returns
#N/A.
Basic CONVERT Example
This example demonstrates converting inches to centimeters using the CONVERT function.
| A | B |
|---|---|
| 10 | |
| =CONVERT(A1, "in", "cm") |
The table shows a length in inches in cell A1 and the conversion formula in B2 that converts it to centimeters. Because 1 inch equals exactly 2.54 centimeters, the result is 25.4 cm.
=CONVERT(10, "in", "cm")
This formula converts 10 inches to centimeters and returns 25.4. Note that unit codes must be enclosed in quotation marks.
Case-Sensitive Unit Codes
Unit names and prefixes are case-sensitive. "m" is the meter, but "M" is the
mega prefix; "C" is degrees Celsius, but "c" is the thermodynamic calorie; "K"
is kelvin, but "k" is the kilo prefix. A single wrong letter changes the meaning
of a formula or produces #N/A.
| Code | Meaning | Common Mistake |
|---|---|---|
| "m" | meter | "M" is the mega prefix, not meter |
| "C" | degree Celsius | "c" is the thermodynamic calorie |
| "K" | kelvin | "k" is the kilo prefix |
| "l" or "L" | liter | Both forms are valid; "lt" also works |
| "in" | inch | "inch" is not a valid code |
| "lbm" | pound mass | "lb" is not a valid code |
| "mn" or "min" | minute | "m" alone means meter |
| "HP" or "h" | horsepower | "hp" is not a valid code |
When in doubt, copy the unit code from Excel's formula autocomplete or from the official documentation instead of typing it from memory.
Temperature Conversion
Temperature conversion is different from the other categories because the
scales do not share a zero point. CONVERT applies the offset as
well as the ratio, so 0 degrees Celsius returns 32 degrees Fahrenheit.
| A | B |
|---|---|
| 100 | |
| =CONVERT(A1, "C", "F") |
The table shows a temperature value in Celsius in cell A1 and the conversion formula in B2 that converts it to Fahrenheit. The result is 212 degrees Fahrenheit.
=CONVERT(A1, "C", "F")
This formula converts the Celsius value in A1 to Fahrenheit. Temperature conversions use "C" for Celsius, "F" for Fahrenheit, "K" for kelvin, "Rank" for degrees Rankine, and "Reau" for degrees Reaumur. The conversion is affine: it multiplies by the scale ratio and then adds an offset, which is why 0 C is 32 F rather than 0 F.
| Formula | Result |
|---|---|
| =CONVERT(0, "C", "F") | 32 |
| =CONVERT(100, "C", "F") | 212 |
| =CONVERT(68, "F", "C") | 20 |
| =CONVERT(0, "C", "K") | 273.15 |
Weight and Mass Conversion
This example demonstrates converting pounds to kilograms, a common mass conversion needed in many applications.
| A | B |
|---|---|
| 150 | |
| =CONVERT(A1, "lbm", "kg") |
The table shows a mass in pounds (lbm stands for pound-mass) in cell A1 and the conversion to kilograms in B2. Because 1 pound-mass equals exactly 0.45359237 kilograms, the result is approximately 68.0389 kg.
=CONVERT(A1, "lbm", "kg")
This formula converts pounds (lbm) to kilograms (kg). Other mass units include "g" for gram, "ozm" for ounce mass, "sg" for slug, "u" for atomic mass unit, "grain", "stone", and "ton". Do not confuse "ozm" (ounce mass) with "oz", which is the fluid ounce used for volume.
Volume Conversion
Volume conversion is useful in cooking, chemistry, and other fields. This example converts US gallons to liters.
| A | B |
|---|---|
| 5 | |
| =CONVERT(A1, "gal", "l") |
The table demonstrates converting 5 gallons to liters. Because the US liquid gallon equals exactly 3.785411784 liters, the result is approximately 18.9271 liters.
=CONVERT(A1, "gal", "l")
This formula converts gallons (gal) to liters (l). The unit "gal" is the US liquid gallon; the imperial gallon has its own code, "uk_gal", and equals 4.54609 liters. Other volume units include "tsp" for teaspoon, "tbs" for tablespoon, "oz" for fluid ounce, "cup", "pt" for US pint, "uk_pt" for UK pint, "qt" for quart, and "m3" for cubic meter. The liter may be written as "l", "L", or "lt".
Energy Conversion
Energy conversion is important in physics and engineering. This example converts joules to calories.
| A | B |
|---|---|
| 1000 | |
| =CONVERT(A1, "J", "cal") |
The table shows 1000 joules being converted to calories. Excel's "cal" is the International Table (IT) calorie, equal to exactly 4.1868 joules, so the result is approximately 238.8459 calories.
=CONVERT(A1, "J", "cal")
This formula converts joules (J) to IT calories (cal). The thermodynamic
calorie has a different code, "c", and equals exactly 4.184 joules, so
=CONVERT(1000, "J", "c") returns approximately 239.0057. Other
energy units include "eV" for electron volt, "Wh" for watt-hour, "HPh" for
horsepower-hour, "flb" for foot-pound, "e" for erg, and "BTU" for British
thermal unit. Since 1 watt-hour equals 3600 joules,
=CONVERT(1, "Wh", "J") returns 3600.
Time Conversion
Time conversions use exact, familiar ratios. The minute code is "mn" (or "min"), and the second code is "sec" (or "s").
| Formula | Result |
|---|---|
| =CONVERT(1, "day", "hr") | 24 |
| =CONVERT(1, "day", "sec") | 86400 |
| =CONVERT(1, "hr", "mn") | 60 |
| =CONVERT(90, "mn", "hr") | 1.5 |
| =CONVERT(1, "yr", "day") | 365.25 |
The year "yr" is treated as 365.25 days, so the average length of a leap year is built in. This is worth remembering when a time conversion looks slightly off by a quarter of a day.
Common Conversion Examples
The following table collects exact factors for the conversions that appear most often in spreadsheets.
| Conversion | Formula | Result |
|---|---|---|
| Inches to centimeters | =CONVERT(1, "in", "cm") | 2.54 |
| Feet to meters | =CONVERT(1, "ft", "m") | 0.3048 |
| Yards to meters | =CONVERT(1, "yd", "m") | 0.9144 |
| Miles to kilometers | =CONVERT(1, "mi", "km") | 1.609344 |
| Pounds to kilograms | =CONVERT(1, "lbm", "kg") | 0.45359237 |
| Ounces to grams | =CONVERT(1, "ozm", "g") | 28.349523125 |
| US gallons to liters | =CONVERT(1, "gal", "l") | 3.785411784 |
| Imperial gallons to liters | =CONVERT(1, "uk_gal", "l") | 4.54609 |
| Watt-hours to joules | =CONVERT(1, "Wh", "J") | 3600 |
| IT calories to joules | =CONVERT(1, "cal", "J") | 4.1868 |
| Atmospheres to pascals | =CONVERT(1, "atm", "Pa") | 101325 |
| Celsius to Fahrenheit | =CONVERT(100, "C", "F") | 212 |
Supported Unit Categories
The CONVERT function supports the measurement categories in this
table. Each has specific unit codes that must be used exactly as defined.
| Category | Example Units |
|---|---|
| Weight and Mass | "g", "kg", "lbm", "ozm", "sg", "stone", "ton" |
| Distance | "m", "mi", "in", "ft", "yd", "ang", "ly", "parsec" |
| Area | "m2", "ft2", "in2", "mi2", "ha", "ar" |
| Time | "yr", "day", "hr", "mn", "sec" |
| Pressure | "Pa", "atm", "mmHg", "psi", "Torr" |
| Force | "N", "dyn", "lbf" |
| Energy | "J", "eV", "cal", "c", "Wh", "BTU" |
| Power | "W", "HP", "PS" |
| Magnetism | "T", "ga" |
| Temperature | "C", "F", "K", "Rank", "Reau" |
| Volume | "tsp", "tbs", "oz", "cup", "gal", "l", "m3" |
| Speed | "m/s", "m/h", "mph", "kn", "admkn" |
| Information | "bit", "byte" |
Metric units accept decimal prefixes such as "k" (kilo), "c" (centi), and "m" (milli), so "km" is a kilometer and "mg" is a milligram. Prefixes are case-sensitive too, and not every unit accepts every prefix.
CONVERT Errors and Troubleshooting
Most CONVERT problems come from misspelled, mismatched, or
incorrectly cased unit codes.
| Cause | Symptom | Fix |
|---|---|---|
| Unit code does not exist | #N/A error | Use the exact code, for example "in" instead of "inch" |
| Units belong to different categories | #N/A error | Convert within one category, such as "kg" to "lbm" |
| Wrong letter case | #N/A error or a different unit | Match case exactly: "C" is Celsius, "c" is a calorie |
| Binary prefix on an unsupported unit | #N/A error | Remove the binary prefix or use a decimal prefix |
| The number argument is text | #VALUE! error | Provide a number, or convert the text with VALUE first |
| Unit code is not quoted | #NAME? error | Wrap both unit codes in double quotation marks |
| Too few or too many arguments | Formula error on entry | Supply exactly number, from_unit, and to_unit |
The most common single mistake is assuming that a plain English word is a valid
unit. "inch", "pound", "gallon", and "minute" are not codes; the codes are
"in", "lbm", "gal", and "mn". When a conversion unexpectedly returns
#N/A, check the spelling and case of both unit arguments before
looking anywhere else.
=CONVERT(10, "in", "cm") ' 25.4, valid codes
=CONVERT(10, "inch", "cm") ' #N/A, "inch" is not a code
=CONVERT(10, "kg", "m") ' #N/A, different categories
=CONVERT("ten", "lbm", "kg") ' #VALUE!, number is text
=CONVERT(10, "lb", "kg") ' #N/A, "lb" is not a code
The CONVERT function is an essential tool for anyone working with
multiple measurement systems in Excel. From simple distance conversions to
complex engineering calculations, it provides accurate results quickly. The key
to using it well is remembering that unit codes are case-sensitive text strings
drawn from a fixed list, that both units must come from the same category, and
that temperature is the one category where an offset is applied. Verify the
unit codes against the official list and test a conversion with a known value
before trusting it in a larger workbook.
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