Free Hex to Decimal Converter – Convert Hexadecimal Online
Convert hexadecimal numbers to decimal instantly. Supports large numbers using BigInt. Works with or without 0x prefix. 100% free, browser-based.
What Is Hexadecimal?
Hexadecimal (hex) is a base-16 number system using digits 0-9 and letters A-F. It's commonly used in computing for:
- Memory addresses
- Color codes (CSS)
- MAC addresses
- Binary data representation
How to Use This Tool
Step 1: Enter Hex
Type a hexadecimal value (e.g., FF or 0xFF)
Step 2: View Result
See the decimal equivalent instantly
Step 3: Copy
Click copy to clipboard
Conversion Examples
| Hexadecimal | Decimal | Use Case |
|---|---|---|
| FF | 255 | Max byte value |
| 100 | 256 | 1 byte overflow |
| FFFF | 65,535 | Max 16-bit value |
| FFFFFF | 16,777,215 | CSS white color |
| FFFFFFFF | 4,294,967,295 | Max 32-bit value |
| DEADBEEF | 3,735,928,559 | Debug marker |
Understanding Hex
Why Base 16?
Each hex digit represents 4 binary bits (a nibble). This makes hex convenient for:
- Representing bytes (2 hex digits = 8 bits)
- Memory addresses
- Color values
Hex Digits
0 1 2 3 4 5 6 7 8 9 A B C D E F
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Conversion Formula
Each position has a value of 16^n where n is the position from right (starting at 0).
Example: 1A3 to decimal
- 1 × 16² = 1 × 256 = 256
- A × 16¹ = 10 × 16 = 160
- 3 × 16⁰ = 3 × 1 = 3
- Total: 256 + 160 + 3 = 419
Common Uses
Web Development
CSS color codes use hex: #FF5733
Programming
Memory addresses, byte arrays, debug values
Networking
MAC addresses: 00:1A:2B:3C:4D:5E
Cryptography
Hash values, encryption keys
Technical Details
Large Number Support
Uses JavaScript BigInt for numbers larger than 2^53.
Input Formats Accepted
FF(plain hex)0xFF(with prefix)0XFF(uppercase prefix)
Frequently Asked Questions
What if I enter invalid characters?
Only 0-9 and A-F are valid. Other characters show an error.
What's the maximum value?
No practical limit thanks to BigInt support.
Is my data secure?
Yes. All processing is client-side.
Related Tools
- Decimal to Hex — Reverse conversion
- Binary to Decimal — Binary converter
- Hex to RGB — Color conversion
- Text to Hex — Encode text
Enter a hexadecimal value above to convert to decimal.