100% Private & Secure
Binary to Decimal Converter
Free online Binary to Decimal Converter for 2026. Convert binary numbers to decimal and decimal to binary instantly — with step-by-step breakdowns, BigInt support, 100% browser-based.
Enter one or more binary numbers separated by spaces or new lines. Supports very large numbers via BigInt.
How Binary to Decimal Conversion Works
Binary (base-2) uses only digits 0 and 1. Each position represents a power of 2, starting from 2⁰ = 1 on the right. To convert to decimal, multiply each digit by its power of 2 and sum the results.
Example: 1011 → decimal
1 × 2³ = 1 × 8 = 8
0 × 2² = 0 × 4 = 0
1 × 2¹ = 1 × 2 = 2
1 × 2⁰ = 1 × 1 = 1
Total = 8 + 0 + 2 + 1 = 11
Binary ↔ Decimal Reference Table
| Binary | Decimal | Hex | Power of 2 |
|---|---|---|---|
| 0000 0001 | 1 | 01 | 2⁰ |
| 0000 0010 | 2 | 02 | 2¹ |
| 0000 0100 | 4 | 04 | 2² |
| 0000 1000 | 8 | 08 | 2³ |
| 0001 0000 | 16 | 10 | 2⁴ |
| 0100 0000 | 64 | 40 | 2⁶ |
| 1000 0000 | 128 | 80 | 2⁷ |
| 1111 1111 | 255 | FF | 2⁸−1 |
Related Tools
Binary to Text
Convert binary code to readable characters
Binary to Hex
Convert binary numbers to hexadecimal
Hex to Text
Decode hexadecimal to readable text
Decimal to Text
Convert decimal code points to characters
ASCII to Text
Decode decimal ASCII codes to characters
ASCII Table
Full 128-character reference chart
Frequently Asked Questions
How do I convert binary to decimal?
Multiply each binary digit by its power of 2, starting from 2⁰ on the right. Sum the results. For example, 1010 = 1×8 + 0×4 + 1×2 + 0×1 = 10.
What is binary 1111 in decimal?
Binary 1111 equals decimal 15. It is 1×8 + 1×4 + 1×2 + 1×1 = 15.
What is binary 10000000 in decimal?
Binary 10000000 equals decimal 128. It is 2⁷ = 128 — the value of the sign bit in a signed 8-bit integer.
Can I convert decimal to binary?
Yes. Switch to the Decimal to Binary tab and enter any decimal number. The result appears instantly.
Does this support large numbers?
Yes. The converter uses JavaScript BigInt, which supports arbitrarily large binary and decimal values — far beyond the 64-bit integer limit.
Is my data safe?
Yes. All conversion runs locally in your browser using JavaScript. Nothing is sent to any server.