Number to Words – Convert Numbers into English Words

About this tool

Convert any number into spelled-out English words — including thousands, millions, billions, decimals and negatives — with an optional uppercase mode. Useful for invoices, cheques, tests, form validation and learning place value. Everything runs locally in your browser; nothing is uploaded.

How to use
  1. Enter a number, for example 123 or 1234.5.
  2. Read the number converted into English words.
  3. Toggle uppercase if you need it in capitals, then copy the result.
Does the number leave my browser?

No. The conversion happens entirely in your browser.

How large a number can be converted?

Up to 999,999,999,999,999 (just under a quadrillion). Larger numbers are flagged rather than converted.