A billion is a thousand million in modern English (short scale). Older British usage once meant a million million, but that has long been replaced.
How to use the Million to Billion Converter
- Type the number of million into the Million field. Decimals such as 500 are fine.
- Read the answer in Billion – it updates as you type, with no button to press.
- To convert the other way, type into Billion and the million are recalculated.
- Press Copy results to copy both values with the page title, or Copy link to share this exact conversion.
This page converts only million ⇄ billion. Need a different unit? Use the general number converter, where you can choose any “from” and “to” unit.
How it works
Both units measure number, so they are always in the same ratio: one million equals 0.001 billion. The calculator multiplies the number of million you type by 0.001 to give billion, and when you type into the billion field it divides by the same factor to give million. Because the ratio never changes, doubling the million always doubles the billion. Results are calculated at full precision and rounded only for display (up to eight decimal places, with very large or small values shown in scientific notation).
How to convert million to billion
- Write down the value in million, for example 1,000 million.
- Multiply by the conversion factor 0.001 (because 1 million = 0.001 billion).
- 1,000 × 0.001 = 1 billion.
- To go back from billion to million, divide by 0.001 – or multiply by 1,000.
million to billion conversion table
| Million | Billion | Billion | Million |
|---|---|---|---|
| 1 million | 0.001 billion | 1 billion | 1,000 million |
| 10 million | 0.01 billion | 2 billion | 2,000 million |
| 100 million | 0.1 billion | 5 billion | 5,000 million |
| 250 million | 0.25 billion | 10 billion | 10,000 million |
| 500 million | 0.5 billion | 20 billion | 20,000 million |
| 1,000 million | 1 billion | 50 billion | 50,000 million |
| 2,500 million | 2.5 billion | 100 billion | 100,000 million |
| 10,000 million | 10 billion | 1,000 billion | 1,000,000 million |
What is a million?
A million is 10⁶ (1,000,000), equal to ten lakh.
What is a billion?
A billion is 10⁹ (1,000,000,000) in the short scale used in English today, equal to 100 crore.
Common mistakes to avoid
Misreading south asian digit grouping (1,00,00,000) as international grouping, and the old british “long scale” billion (10¹²), no longer in use.
Formula
1 million = 0.001 billion1 billion = 1,000 millionbillion = million × 0.001Worked example
Inputs — Million: 1,000 million.
Results — Billion = 1 billion.
Frequently asked questions
How many millions in a billion?
1,000.
What is 2,500 million?
2.5 billion.
How many billion are in one million?
1 million = 0.001 billion.
How many million are in one billion?
1 billion = 1,000 million.
How do I convert million to billion?
Multiply the number of million by 0.001. For example, 1,000 million × 0.001 = 1 billion.
How do I convert billion back to million?
Divide by 0.001 (or multiply by 1,000), or simply type the value into the billion field above.
What is 10 million in billion?
10 million = 0.01 billion.
What is 100 million in billion?
100 million = 0.1 billion.
Is this conversion exact?
Yes. The factor comes from the official definitions of both units (NIST and the SI), so the only difference you may see is rounding in the last displayed digit.
Can I convert to other units on this page?
This page converts only between million and billion. To pick any number unit, use the general number converter linked under Related calculators.
What formula does the Million to Billion Converter use?
1 million = 0.001 billion.