What They Do
LOWER converts every letter in a text string to lowercase. UPPER converts every letter to uppercase. PROPER capitalizes the first letter of each word and lowercases the rest. These three functions are essential for standardizing inconsistent data — whether you are cleaning up a mailing list, normalizing product names, or preparing data for a case-sensitive lookup.
Syntax
=LOWER(text)
=UPPER(text)
=PROPER(text)
| Parameter | Description |
|---|---|
| text | The string or cell reference to convert. |
Each function takes a single argument and returns the transformed text. Numbers, punctuation, and spaces pass through unchanged.
Basic Examples
Standardize email addresses to lowercase
| A | B | |
|---|---|---|
| 1 | Cleaned | |
| 2 | John.Doe@EXAMPLE.COM | =LOWER(A2) |
| 3 | SARA@Company.IO | =LOWER(A3) |
Results in column B:
Convert product codes to uppercase
| A | B | |
|---|---|---|
| 1 | Code | Standardized |
| 2 | sku-a204 | =UPPER(A2) |
| 3 | Sku-b118 | =UPPER(A3) |
Results:
| Standardized |
|---|
| SKU-A204 |
| SKU-B118 |
Format names with PROPER
| A | B | |
|---|---|---|
| 1 | Name | Formatted |
| 2 | MARIA GONZALEZ | =PROPER(A2) |
| 3 | james o'brien | =PROPER(A3) |
Results:
| Formatted |
|---|
| Maria Gonzalez |
| James O'Brien |
PROPER recognizes apostrophes and hyphens as word boundaries, so o'brien becomes O'Brien.
Advanced Examples
Case-insensitive comparison
Google Sheets string comparisons are case-insensitive by default, but if you ever need to enforce a match explicitly — or you are building a formula for export — wrapping both sides in LOWER (or UPPER) guarantees consistency:
=IF(LOWER(A2) = LOWER(B2), "Match", "No match")
This avoids surprises when data comes from different sources with different casing conventions.
Capitalize only the first letter of a sentence
PROPER capitalizes every word, which is not always what you want. To capitalize just the first letter of a string while lowering everything else:
=UPPER(LEFT(A1, 1)) & LOWER(MID(A1, 2, LEN(A1)))
For A1 = "the QUICK brown FOX", this returns The quick brown fox. It takes the first character, uppercases it, and appends the rest in lowercase.
Common Mistakes
- Expecting PROPER to handle acronyms correctly. PROPER will turn
"NASA engineer"into"Nasa Engineer". It does not know that NASA should stay fully capitalized. You would need a manual fix or a SUBSTITUTE workaround for known acronyms. - Forgetting that these functions return text, not modify the original. The source cell stays the same. To replace the originals, copy the result column and paste it over the source using Paste Special > Values Only, then delete the helper column.
- Using PROPER on data with mixed delimiters. PROPER treats spaces, hyphens, and apostrophes as word separators, but not underscores or periods.
"john.smith"becomes"John.smith"— only the first letter after the period is not capitalized as expected. Clean the delimiter first with SUBSTITUTE if needed.
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