Binary to Decimal Converter
Convert Binary () to Decimal () with this free calculator. Type a value, press Convert, and the page applies the same factor shown in the formula below — no rounded shortcut, and nothing is stored on a server.
How to convert Binary to Decimal
Convert binary to decimal by summing powers of 2.
d = b_{n-1}×2^{n-1} + ... + b_1×2^1 + b_0×2^0
Each binary digit (from right) represents a power of 2:
Example: Convert 1010₂ to decimal:
1010₂ = 1×2³ + 0×2² + 1×2¹ + 0×2⁰ = 8+0+2+0 = 10
What is a Binary?
The Binary () is the starting or target unit on this page. Use the calculator above to convert values without looking up the factor by hand.
What is a Decimal?
The Decimal () is the starting or target unit on this page. Use the calculator above to convert values without looking up the factor by hand.
This page converts number systems from Binary into Decimal. Use the formula above for the exact relationship between the two units.
Binary to Decimal conversion table
Common values and the matching result, calculated with the same factor as the widget. Highlight a nearby row if you want a quick check without entering a number.
| Binary () | Decimal () |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 10 | 2 |
| 11 | 3 |
| 100 | 4 |
| 101 | 5 |
| 110 | 6 |
| 111 | 7 |
| 1000 | 8 |
| 1001 | 9 |
| 1010 | 10 |
| 1011 | 11 |
| 1100 | 12 |
| 1101 | 13 |
| 1110 | 14 |
| 1111 | 15 |
| 10000 | 16 |
| 100000 | 32 |
| 1000000 | 64 |
| 10000000 | 128 |
| 11111111 | 255 |
How this calculator works
The form on this page is a Binary-to-Decimal converter. After you enter a number, JavaScript multiplies or rearranges it with the published conversion factor and writes the result in the output box. The step-by-step panel repeats the arithmetic so you can copy it into homework or a spreadsheet.
Reviewed by Hamsen, founder of GigaTables and a biology engineer. See the about page for how formulas are checked before a tool is published.
FAQ
How many are in 1 ?
Use the formula in the section above. Temperature and logarithmic units are not a single multiply-by-a-constant step.
How do I convert Binary to Decimal?
Each binary digit (from right) represents a power of 2:
Is this to converter free?
Yes. GigaTables calculators are free to use in a browser. You do not need an account, and the values you type are not uploaded.