The direct answer
A trillion has 12 zeros: 1,000,000,000,000 = 1012.
A trillion is 1,000 billion or 1,000,000 million. Its five comma-separated periods are trillions, billions, millions, thousands and ones.
See the zeros in groups of three
Start with the 1 and count the zero groups to its right. Each complete group contributes three zeros, so 4 groups × 3 zeros = 12 zeros.
Previous and next named numbers
| Position | Name | Written number | Power |
|---|---|---|---|
| Previous | billion | 1,000,000,000 | 109 |
| Current | trillion | 1,000,000,000,000 | 1012 |
| Next | quadrillion | 1,000,000,000,000,000 | 1015 |
Each move to the right multiplies the number by 1,000 and adds three zeros.
How to say and write trillion
The number 1,000,000,000,000 is written in words as one trillion. A number such as 2,000,000,000,000 is two trillion; the scale word itself does not become plural inside a number name.
Short-scale note: Big Number Playground uses the modern English short scale, where billion is 109 and each new “illion” is 1,000 times the previous one.
Explore related large numbers
Use the Big Number Explorer to convert any whole number to words, or continue with the large number names chart and the million, billion and trillion comparison.