Despite its age, Excel continues to evolve with new functions being added over time. There are newer betterExcel functions that you should use instead of the old ones. But, there are also some old Excel functions that you don't need to stop using — because you never used them to begin with.

Excel remains a relic, despite all its updates. That’s because Excel never removes functions; every new one is simply added to the existing pile. It makes sense when you consider the compability issues (what if a company still uses a spreadsheet they made twenty years ago?) but it also provides some really interesting snapshots of its history. I went looking, got lost in the maze, and came back with a handful of Excel functions that I'm sure no one uses today.

BAHTTEXT

I can do your invoices in Bangkok

=BAHTTTEXT(number)

BAHTTEXT converts a number into Thai Baht words. For example,=BAHTTEXT(472.50) returnsสี่ร้อยเจ็ดสิบสองบาทห้าสิบสตางค์, which meansfour hundred seventy-two Baht and fifty Satang.

This function was introduced for Thailand’s accounting and invoicing standards, where monetary values are often written in both numeric and textual form to prevent fraud or misreading. It’s the only language-specific number-to-text function built into Excel, although Thailand is not the only country to write both numeric and textual values in official forms. Oddly, Microsoft didn't add this support for any other country.

Obviously, outside Thailand, BAHTTEXT serves little purpose, but it still exists in every version of Excel. You can't change the language output — it will always produce Thai text. It's literally in the name.

ROMAN

Spreadsheets with delusions of empire

=ROMAN(number, [form])

ROMAN converts Arabic numerals into Roman numerals. For example,=ROMAN(2025) returnsMMXXV. The optional[form] argument (0–4) controls the level of abbreviation. A higher value produces more compact forms (for example, 499 asID instead ofCDXCIX).

This function dates back to early versions of Excel, when Roman numerals were occasionally used for page numbering, outlines, or formal documents. In modern use, it’s decorative at best. It still works flawlessly but is rarely applied to any real-world data. Most people who rediscover it are either exploring Excel’s function list out of curiosity, or writing their personal manifesto in Excel.

ARABIC

Regret button for anyone who used ROMAN unironically

=ARABIC(text)

ARABIC reverses the work of ROMAN. It converts a Roman numeral string back to a standard number. For instance=ARABIC("MMXXV") returns2025. It’s one of Excel’s few “complementary” functions which directly undoes another.

ARABIC was added much later than ROMAN, primarily for data compatibility. If a user inherited legacy spreadsheets using Roman numerals, this function allowed them to bring the data back into numeric form. Today, it’s a curiosity. The only practical reason to use it is to fix a cell that someone (needlessly) converted with ROMAN in the first place.

PHONETIC

Works only if you live in Tokyo

=PHONETIC(reference)

PHONETIC extracts phonetic text (calledfurigana) from East Asian character data. In Japanese versions of Excel, users can attach pronunciation guides to kanji text using the Phonetic Guide feature.

I don't speak (or read) Japanese, but I tried installing the Japanese language pack to try this out. The feature should appear under the Fonts group on the Home tab, but it didn't show up. I tried customizing the Excel ribbon to manually add it and it worked. I did get a Phonetics Guide feature, but clicking it did nothing. I suppose this feature is really locked to the region.

Despite this, the PHONETIC function itself (which is useless without the underlying phonetic system) is available in all versions of Excel.

INFO

Excel, but self-aware

=INFO(type_text)

INFO returns information about the current Excel environment. Thetype_text argument must be one of a predefined set of keywords such as:

For example,=INFO("osversion") returnsWindows (64-bit) NT 10.00 for me. Originally, INFO was useful forExcel macros and automated spreadsheets that needed to adapt based on environment variables. Today, the same data can be accessed more reliably through VBA or Power Query, which makes INFO largely irrelevant for modern workflows.

DBCS and ASC

From the encoding wars

=DBCS(text)=ASC(text)

These two functions convert text between double-byte and single-byte character encodings. They exist for legacy East Asian systems that distinguished between half-width (single-byte) and full-width (double-byte) characters. For example,=ASC("ＭＵＯ") returns the single-byte versionMUO. Whereas,=DBCS("MUO") returns the double-byteＭＵＯ.

Before Unicode, certain Japanese and Chinese characters required two bytes per symbol, while Western letters used one. When data moved between systems that interpreted text widths differently, these conversions prevented corruption.

In the Unicode era, both functions are practically obsolete. They still appear for backward compatibility, especially when opening old CSV files from Japanese financial software or mainframe exports. Given Japan’s rapid economic expansion in the 1990s, Microsoft’s decision to include and preserve these features makes sense.

DOLLARDE and DOLLARFR

Wall Street fossils

=DOLLARDE(fractional_dollar, fraction)=DOLLARFR(decimal_dollar, fraction)

These two are remnants of the financial world’s pre-decimal era. They're also the most interesting to me, because learning their purpose turned into an impromptu history lesson: U.S. bonds and some stock prices were once quoted in fractions rather than decimals (typically in sixteenths or thirty-seconds). For example, a bond price might appear as 101 8/32. This means $101 and 8/32 of a dollar, or $101.25 in today's notation.

DOLLARDE converts fractional dollar values to decimal form, while DOLLARFR does the reverse. For instance,=DOLLARDE(1.02,16) returns1.125, and=DOLLARFR(1.125,16) returns1.02.

These conversions allowed analysts to run calculations on legacy data without rewriting pricing systems. Since modern markets use decimals, both functions now survive mostly for historical completeness. They remain accurate but have almost no practical application outside of reconstructing vintage financial records.

The old gods of Excel

I had a blast looking these up and writing about them, and I hope you enjoyed the ride too. There's little practical value here — you will (likely) never use any of these, but that's precisely what makes them fascinating. They survive as fossils in the codebase and made me appreciate Excel's history more. So, the next time you open a new workbook, remember: buried in Excel's formula tabs is the story of how humans tried to make numbers speak every language on Earth.