How Many Zeros in a Billion?
A billion has 9 zeros, written as 1,000,000,000. In scientific notation that is 109, making a billion the smallest 10-digit number. Under the short scale system used throughout the English-speaking world, one billion equals one thousand million. Some older European references used a long scale where "billion" meant one million million (12 zeros), but that definition is obsolete in contemporary English — today 9 zeros is the universal standard. Related: Zeros in a million.
A billion has
9
zeros
- Written Form
- 1,000,000,000
- Scientific
- 10⁹
Is a Billion 9 Zeros or 12 Zeros?
In modern English, a billion always has 9 zeros. The confusion arises from two historical numbering conventions that existed side by side for much of the 20th century. See also: How many zeros does a number have.
The short scale — used in the United States, United Kingdom, and most English-speaking countries — defines a billion as 1,000,000,000 (109), where each named number is one thousand times the previous one. The long scale, used historically in parts of continental Europe, defined a billion as 1,000,000,000,000 (1012) — what short-scale speakers call a trillion. The United Kingdom officially switched to the short scale in 1974. Today every major financial institution, news organisation, and government body in the English-speaking world uses the 9-zero definition.
How Many Zeros in 10 Billion and 100 Billion?
Multiplying a billion by 10 adds one zero each time. The table below shows how the zero count grows as you scale up from one billion toward a trillion.
| Amount | Written Out | Zeros |
|---|---|---|
| 1 billion | 1,000,000,000 | 9 |
| 10 billion | 10,000,000,000 | 10 |
| 100 billion | 100,000,000,000 | 11 |
| 1,000 billion | 1,000,000,000,000 | 12 (= 1 trillion) |
So 100 billion has 11 zeros. It is written as 100,000,000,000 — the base billion (9 zeros) multiplied by 100, which contributes two additional zeros. Once you reach 1,000 billions you arrive at a trillion (12 zeros).