IP Address Converter — IPv4 to Binary & Decimal Free
Need to convert an IP address to binary, decimal, or hexadecimal? Our free IP Address Converter handles all IPv4 format conversions instantly. Whether you're studying networking, configuring subnets, analyzing firewall rules, or debugging network issues — this tool converts between dotted-decimal, binary, decimal integer, hexadecimal, and octal representations with a single click.
What is an IP Address?
An IP (Internet Protocol) address is a unique numerical identifier assigned to every device connected to a computer network. Just as a street address identifies a building's location, an IP address identifies a device's location on a network, enabling data to be routed to the correct destination.
Every device that connects to the internet — your computer, smartphone, smart TV, IoT devices, and web servers — has at least one IP address. Routers use these addresses to forward data packets between networks, ensuring information reaches the right destination across the global internet.
IPv4 vs. IPv6
| Feature | IPv4 | IPv6 |
|---|---|---|
| Address size | 32 bits | 128 bits |
| Total addresses | ~4.3 billion | ~3.4 × 10³⁸ |
| Format | Dotted decimal (192.168.1.1) | Hex groups (2001:db8::1) |
| Example | 172.16.254.1 | fe80::1ff:fe23:4567:890a |
| Header size | 20-60 bytes | 40 bytes (fixed) |
| NAT required | Often yes | Generally no |
| Adoption | ~60% of traffic | ~40% of traffic |
IPv4 remains dominant but its limited address space (4.3 billion addresses) was exhausted years ago. IPv6 was designed to solve this with a virtually unlimited address space. Most modern systems support both (dual-stack).
Binary Representation of IPv4
An IPv4 address is internally a 32-bit number. The familiar dotted-decimal notation (like 192.168.1.1) is a human-readable representation where each of the four octets shows the decimal value of 8 bits:
IP: 192.168.1.1
Octet 1: 192 = 11000000
Octet 2: 168 = 10101000
Octet 3: 1 = 00000001
Octet 4: 1 = 00000001
Full binary: 11000000.10101000.00000001.00000001
Decimal integer: 3232235777
Hexadecimal: C0.A8.01.01
Each octet ranges from 0 (00000000) to 255 (11111111). Understanding binary is essential for working with subnet masks, CIDR notation, and network troubleshooting.
Subnet Masks Explained
A subnet mask determines which portion of an IP address identifies the network and which identifies the host (individual device). It's a 32-bit number with consecutive 1-bits followed by consecutive 0-bits:
- 255.255.255.0 (/24): First 24 bits = network, last 8 bits = host. Supports 254 hosts. Most common for home/office networks.
- 255.255.0.0 (/16): First 16 bits = network, last 16 bits = host. Supports 65,534 hosts. Used for larger organizations.
- 255.0.0.0 (/8): First 8 bits = network, last 24 bits = host. Supports 16+ million hosts. Used for very large networks.
- 255.255.255.128 (/25): Splits a /24 into two subnets of 126 hosts each.
The subnet mask works by performing a bitwise AND operation with the IP address to extract the network address. Bits where the mask is 1 belong to the network; bits where it's 0 identify the host.
CIDR Notation
CIDR (Classless Inter-Domain Routing) notation is a compact way to express an IP address and its associated subnet mask. Instead of writing the full subnet mask, you append a slash followed by the number of network bits:
| CIDR | Subnet Mask | Usable Hosts | Typical Use |
|---|---|---|---|
| /32 | 255.255.255.255 | 1 | Single host route |
| /30 | 255.255.255.252 | 2 | Point-to-point link |
| /28 | 255.255.255.240 | 14 | Small office |
| /24 | 255.255.255.0 | 254 | Standard LAN |
| /16 | 255.255.0.0 | 65,534 | Large organization |
| /8 | 255.0.0.0 | 16,777,214 | ISP / Class A |
Public vs. Private IP Addresses
Not all IP addresses are accessible from the internet. Private addresses are reserved for internal networks and cannot be routed on the public internet:
- 10.0.0.0 – 10.255.255.255 (/8) — 16 million addresses. Enterprise networks.
- 172.16.0.0 – 172.31.255.255 (/12) — 1 million addresses. Medium organizations.
- 192.168.0.0 – 192.168.255.255 (/16) — 65,536 addresses. Home/small office routers.
Public addresses are globally unique and routable on the internet. Your router's external IP is public; devices behind it use private addresses and communicate externally through NAT (Network Address Translation).
Conversion Examples
| Dotted Decimal | Binary | Decimal Integer | Hexadecimal |
|---|---|---|---|
| 192.168.1.1 | 11000000.10101000.00000001.00000001 | 3232235777 | C0.A8.01.01 |
| 10.0.0.1 | 00001010.00000000.00000000.00000001 | 167772161 | 0A.00.00.01 |
| 172.16.0.1 | 10101100.00010000.00000000.00000001 | 2886729729 | AC.10.00.01 |
| 255.255.255.0 | 11111111.11111111.11111111.00000000 | 4294967040 | FF.FF.FF.00 |
| 127.0.0.1 | 01111111.00000000.00000000.00000001 | 2130706433 | 7F.00.00.01 |
Special IP Addresses
- 0.0.0.0: Default route /"this network." Used by DHCP clients before receiving an address.
- 127.0.0.1: Loopback (localhost). Tests local network stack without external communication.
- 255.255.255.255: Limited broadcast. Reaches all hosts on the local network segment.
- 169.254.x.x: Link-local (APIPA). Assigned automatically when DHCP fails.
- 224.0.0.0 – 239.255.255.255: Multicast range. Used for group communications (IPTV, mDNS).
Frequently Asked Questions
What is an IP address?
An IP (Internet Protocol) address is a unique numerical identifier assigned to every device connected to a network. It enables devices to find and communicate with each other across local networks and the internet. IPv4 uses 32-bit addresses written as four decimal octets separated by dots (e.g., 192.168.1.1).
How do I convert an IP address to binary?
Convert each of the four octets (numbers between dots) to its 8-bit binary equivalent. Pad each with leading zeros to ensure 8 digits. For example, 192.168.1.1 → 11000000.10101000.00000001.00000001. Our tool does this conversion instantly.
What is the difference between IPv4 and IPv6?
IPv4 uses 32-bit addresses providing about 4.3 billion unique addresses, written in dotted-decimal form. IPv6 uses 128-bit addresses providing 3.4×10³⁸ addresses, written as eight groups of four hexadecimal digits. IPv6 was created because IPv4 addresses have been exhausted.
What is a subnet mask?
A subnet mask divides an IP address into network and host portions. Consecutive 1-bits identify the network; consecutive 0-bits identify individual hosts. For example, 255.255.255.0 (/24) means the first 24 bits are the network address and the remaining 8 bits identify up to 254 individual hosts on that subnet.
What is CIDR notation?
CIDR (Classless Inter-Domain Routing) notation appends a slash and prefix length to an IP address (e.g., 192.168.1.0/24). The number after the slash indicates how many leading bits form the network portion. /24 means 24 network bits and 8 host bits, allowing 254 usable addresses.
What are private IP address ranges?
Private (non-routable) ranges defined in RFC 1918: 10.0.0.0/8 (10.0.0.0–10.255.255.255), 172.16.0.0/12 (172.16.0.0–172.31.255.255), and 192.168.0.0/16 (192.168.0.0–192.168.255.255). These are used within local networks and require NAT to access the internet.
How do I convert an IP address to a decimal number?
Multiply each octet by its positional power of 256: (first × 256³) + (second × 256²) + (third × 256¹) + (fourth × 256⁰). For 192.168.1.1: (192 × 16,777,216) + (168 × 65,536) + (1 × 256) + 1 = 3,232,235,777.
What is the loopback IP address?
The loopback address 127.0.0.1 (and the entire 127.0.0.0/8 range) is reserved for testing network software locally. Traffic sent to 127.0.0.1 never reaches the physical network — it loops back to the same device. It is commonly known as"localhost" and is used for development and diagnostics.
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