Updated: July 2026
Number in Words is a free online tool that writes any number or value in reais in words, ready for use on checks, contracts, receipts and other documents that require the value written in words.
What is it
In many formal documents, such as checks, rental contracts, deeds and receipts, it is not enough to write the number in numbers: you must also write it in full, and the correct spelling avoids erasures and disputes. The problem is that the Portuguese language has several specific rules for large numbers, such as the use of "hundred" or "cento", the preposition "de" before million and billion, and the way the cents part is written.
This tool solves that instantly. Just enter the number or value in reais and the full text appears ready to copy, already formatted, with the grammar rules automatically applied. It works for large numbers, reaching trillions, and also for amounts of money, including cents.
How to use
- Enter the number or value in the indicated field.
- Activate the "Amount in Reais" option if you are writing an amount in money, so the result includes cents in the correct format.
- Choose the text format: normal (with the first letter capitalized), all uppercase or all lowercase, using the Aa, AA and aa buttons.
- Copy the result with the copy button and paste directly into the check, contract or document.
Real-time grammar tips
Whenever the number entered involves a lesser-known grammatical rule, the tool shows a warning explaining the reason for the chosen spelling. For example: when writing a million reais, she explains why it is mandatory to use the preposition "de"; when writing hundred or hundred, it shows the difference between using one or the other; and in amounts in the thousands, she recommends starting with "one thousand" instead of just "one thousand" in documents such as checks, to make fraud more difficult. So, in addition to generating the text, the tool helps you understand the grammatical rule behind it.
Everything is processed directly in your browser, without registration and at no cost, so you can generate as many written values as you need, as many times as you want.