How to Write Numbers in Words: Complete Guide
By WordsForNumbers Editorial Team · Updated 2026-10-10 · 30 min read
Hyphenate compound numbers from twenty-one to ninety-nine, write one hundred five in American English or one hundred and five in British English, and name each group from the left: two million five hundred thousand.
What are the five core rules for writing numbers in words?
- Hyphenate compound numbers from 21 to 99: twenty-one, forty-two, ninety-nine.
- Never add a plural -s to hundred, thousand, million, or billion after a number: two hundred, five thousand.
- In American English, omit "and" inside whole numbers: one hundred five. In British English, include it: one hundred and five.
- Name each three-digit group from the left: 2,500,000 is "two million five hundred thousand".
- Skip groups that are zero: 1,005,000 is "one million five thousand", never "one million zero thousand five thousand".
When do you hyphenate numbers in words?
Hyphenate compound numbers between twenty-one and ninety-nine: twenty-one, thirty-five, eighty-seven. Do not hyphenate round tens (twenty, thirty), hundreds (one hundred), or scale words (one thousand). The Numbers 1 to 100 in Words table shows every hyphenated form.
Do you write "one hundred and five" or "one hundred five"?
Both are correct in different regions. American style guides write one hundred five with no "and". British style writes one hundred and five, and British cheques traditionally require the "and". Pick one convention and use it through the whole document.
How do you write thousands, millions, and billions in words?
Work from the largest group to the smallest and name each group: 45,000 is "forty-five thousand"; 3,200,000 is "three million two hundred thousand"; 7,000,000,000 is "seven billion". Each group follows the same hundred-tens-ones pattern as numbers under one thousand.
The table below shows the pattern across every scale. Read each row left to right to see how the groups combine.
| Figure | In words |
|---|---|
| 0 | zero |
| 7 | seven |
| 13 | thirteen |
| 21 | twenty-one |
| 40 | forty |
| 99 | ninety-nine |
| 100 | one hundred |
| 105 | one hundred five |
| 1,000 | one thousand |
| 1,500 | one thousand five hundred |
| 100,000 | one hundred thousand |
| 2,500,000 | two million five hundred thousand |
| 1,000,000,000 | one billion |
How do you write zero in words?
Use zero in general writing and mathematics. In specific contexts, other words apply: "nil" in sports scores, "nought" in British English, "oh" in phone numbers (0301 is read "oh three oh one"), and "love" in tennis. On cheques and formal documents, always write "zero".
How do you write ordinal numbers in words?
Ordinals name position: first, second, third, fourth, fifth. The teens are irregular (eleventh, twelfth, thirteenth, twentieth), and compound ordinals hyphenate like cardinals: twenty-first, thirty-second, one hundred first. Use ordinals for rankings, dates, and sequences.
When should you use numerals instead of words?
- Measurements, dates, times, and money: 5 kg, 10 March 2026, 3:30 pm, Rs 250.
- Statistics and data: "sales rose 12 percent", "a sample of 400 people".
- Numbers of 10 and above in most news writing (AP style spells out one through nine).
- Tables, charts, and technical documents, where numerals scan faster.
- Spell out numbers at the start of a sentence: "Twenty-five guests attended", never "25 guests attended".
How do Indian and international grouping differ?
The international system groups digits in threes: 1,000,000. The Indian system groups the first three digits, then pairs: 10,00,000 (ten lakh). Full conversion tables, comma rules, and worked examples are in Lakh vs Million, Crore vs Billion — Explained Simply.
What are the most common mistakes?
The costliest errors are missing hyphens ("twenty five"), plural scale words ("two thousands"), misplaced "and", and mixing lakh with million in one document. All thirty documented errors with fixes are listed in 30 Common Mistakes When Writing Numbers in Words (and Fixes).
How do you write decimals in words?
Read 12.45 as "twelve point four five" in speech or "twelve and forty-five hundredths" in formal writing. The full rules for both conventions, trailing zeros, and scientific use are covered in How to Write Decimals in Words.
How can you check a number in words instantly?
Type any figure into the Number to Words Converter to see the exact spelling in International or Indian (lakh/crore) systems. Use it to verify hyphenation, grouping, and scale words before submitting cheques, invoices, or assignments.