Base-4 to Binary Converter
Convert base-4 (quaternary) integers to binary instantly. Enter a base-4 value such as 121 and convert each digit directly into its corresponding 2-bit binary group with decimal verification.
What Is Base-4 to Binary Conversion?
Base-4 to binary conversion changes a quaternary number into an equivalent
base-2 value. Since 4 = 2², every base-4 digit corresponds
exactly to two binary bits.
Base-4 to Binary Conversion Table
| Base-4 Digit | Binary Pair |
|---|---|
| 0 | 00 |
| 1 | 01 |
| 2 | 10 |
| 3 | 11 |
How to Convert Base-4 to Binary
1. Read the base-4 number
Verify that every digit is 0, 1, 2, or 3.
2. Process each digit
Treat each quaternary digit independently.
3. Replace 0 with 00
Base-4 digit 0 maps to binary pair 00.
4. Replace 1, 2 and 3
Use 01 for 1, 10 for 2, and 11 for 3.
5. Join the binary pairs
Keep the converted groups in the same left-to-right order.
6. Remove leading zeros
Unnecessary leading binary zeros can be removed from the integer result.
Example: Convert Base-4 22 to Binary
Example: Convert Base-4 121 to Binary
Base-4 to Binary Examples
| Base-4 | Decimal | Binary |
|---|---|---|
0 | 0 | 0 |
1 | 1 | 1 |
2 | 2 | 10 |
3 | 3 | 11 |
10 | 4 | 100 |
11 | 5 | 101 |
12 | 6 | 110 |
13 | 7 | 111 |
20 | 8 | 1000 |
21 | 9 | 1001 |
22 | 10 | 1010 |
23 | 11 | 1011 |
30 | 12 | 1100 |
33 | 15 | 1111 |
100 | 16 | 10000 |
121 | 25 | 11001 |
Why Does One Base-4 Digit Equal Two Binary Bits?
Four different two-bit binary combinations exist:
Base-4 vs Binary
| Feature | Base-4 | Binary |
|---|---|---|
| Base | 4 | 2 |
| Allowed digits | 0, 1, 2, 3 | 0, 1 |
| Binary mapping | 2 bits per digit | Native bits |
| Decimal 10 | 22 |
1010 |
| Decimal 25 | 121 |
11001 |
Do Leading Base-4 Zeros Matter?
No. Leading zero digits do not affect the numerical value.
Common Base-4 to Binary Mistakes
Using digits above 3
A valid base-4 number can contain only digits 0 through 3.
Using three-bit groups
Each base-4 digit maps to exactly two binary bits.
Converting the whole string as decimal
Base-4 digits use powers of 4, not powers of 10.
Dropping internal zeros
Only unnecessary leading zeros may be removed; internal binary zeros must remain.
Related BinaryCon Tools
Base-4 to Binary Converter FAQs
How do you convert base 4 to binary?
What is base-4 3 in binary?
3 maps directly to binary 11.
What is base-4 11 in binary?
1 → 01, giving 0101.
After removing the leading zero, the result is 101.
What is base-4 22 in binary?
10, so 22₄ = 1010₂.
What is base-4 121 in binary?
01 10 01. Removing the leading zero gives
binary 11001.
Why does every base-4 digit use two binary bits?
4 = 2², so the four possible base-4 digits correspond
exactly to the four possible two-bit combinations.
What digits are valid in base 4?
0, 1, 2, and 3.