What this calculator does
A billion is 1,000 million. That is the whole relationship: in the short scale used in Australia, the UK, the US and most financial reporting today, a billion is a thousand times bigger than a million, and the two never drift relative to each other because both are fixed powers of ten.
This calculator converts million to billion in either direction: enter a number of millions to see how many billions that is, or enter a number of billions to see how many millions it takes to make it up. It is a common stumbling point when reading large budgets, market sizes or population figures, where the difference between "1000 million" and "1 billion" is easy to state but easy to get wrong in your head.
The formula
Converting millions to billions divides by 1,000, since it takes 1,000 million to reach one billion. Converting billions to millions multiplies by 1,000. Both directions use the same fixed factor, so there is nothing to look up beyond that single relationship.
| Term | Meaning |
|---|---|
| Million | One thousand thousand: 1,000,000, or 10⁶. |
| Billion | One thousand million: 1,000,000,000, or 10⁹, under the short-scale definition used here. |
| Short scale | The counting system where each new named unit is 1,000 times the last (million, billion, trillion). It is the standard in modern English-language usage, unlike the older long scale where a billion meant a million million. |
The inputs explained
| Field | What to enter |
|---|---|
| Value | The number of millions or billions you are converting, depending on the direction chosen below. |
| Convert | Choose whether you are converting millions into billions, or billions into millions. |
When to use it
Reading a national budget or company revenue figure
Government spending and large company revenue are often reported in millions in one source and billions in another; converting between the two avoids misreading the scale of a figure by a factor of a thousand.
Comparing population or market-size numbers
A market size quoted as "1000 million to billion" style figures is common in industry reports; restating everything in the same unit makes two reports actually comparable.
Sanity-checking a large number
If a spreadsheet or article states a figure in millions and it seems implausibly large or small, converting it to billions (or vice versa) is a quick way to check whether a unit got dropped somewhere along the way.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How many billions is a given number of millions?
Common million figures and the equivalent number of billions, using 1 billion to million (1,000 million per billion).
How many millions is a given number of billions?
Common billion figures and the equivalent number of millions.
Questions
How many millions are in a billion?
Exactly 1,000, under the short-scale definition used in Australia, the UK, the US and international finance today. This is a fixed relationship, not an approximation.
Is a billion always 1,000 million?
Under the short scale, yes, and that is now the near-universal standard in English-language usage, including UK government and media use since the 1970s. The older long scale, where a billion meant a million million (10¹²), is largely historical outside a few contexts.
How do I convert 1 billion to million?
Multiply by 1,000: 1 billion is 1,000 million. The same factor works in reverse, so 1,000 million divided by 1,000 gives 1 billion.
What comes after a billion?
A trillion, which is 1,000 billion, or a million million. The same ×1,000 step that separates million from billion also separates billion from trillion.
For other simple fixed-factor conversions, see the dozen calculator.