Decimal IP Converter Form
Large screens show three columns, smaller screens show two, and mobile shows one.
Example Data Table
| Decimal | IPv4 | CIDR | Class | Scope |
|---|---|---|---|---|
| 3232235777 | 192.168.1.1 | /24 | Class C | Private |
| 167772161 | 10.0.0.1 | /8 | Class A | Private |
| 2886729728 | 172.16.0.0 | /16 | Class B | Private |
| 2130706433 | 127.0.0.1 | /8 | Loopback | Loopback |
| 4294967295 | 255.255.255.255 | /32 | Class E | Limited Broadcast |
Formula Used
Decimal to IPv4:
Octet 1 = floor(Decimal / 2563)
Octet 2 = floor((Decimal mod 2563) / 2562)
Octet 3 = floor((Decimal mod 2562) / 256)
Octet 4 = Decimal mod 256
IPv4 to Decimal:
Decimal = (O1 × 2563) + (O2 × 2562) + (O3 × 256) + O4
Subnet Calculations:
Subnet Mask = First n bits set to 1 for CIDR /n.
Network Address = IP AND Subnet Mask.
Broadcast Address = Network Address OR Wildcard Mask.
How to Use This Calculator
- Choose whether you want decimal-to-IPv4 or IPv4-to-decimal conversion.
- Enter either the decimal value or the dotted IPv4 address.
- Set a CIDR prefix to calculate subnet mask, network, broadcast, and host range.
- Optionally add a label and notes for exports or documentation.
- Click Convert Now to show results above the form.
- Use the CSV or PDF buttons to save the current output.
Frequently Asked Questions
1. What is a decimal IP value?
A decimal IP value is the unsigned 32-bit integer form of an IPv4 address. It stores all four octets as one number, which is useful in logs, databases, firewall rules, and scripts.
2. Can this calculator convert in both directions?
Yes. You can convert a decimal number into an IPv4 address or enter an IPv4 address and return its decimal value. The same result section also shows subnet-related details.
3. Why does the CIDR prefix matter here?
The CIDR prefix defines the subnet mask. That mask determines the network address, broadcast address, wildcard mask, host range, and the number of usable hosts associated with the input IP.
4. Does the calculator identify private and public ranges?
Yes. It marks common scopes such as private, public, loopback, link-local, multicast, documentation, carrier-grade NAT, and reserved ranges by checking the resulting octets against standard IPv4 blocks.
5. What are IP classes in the result?
IP classes are legacy groupings based on the first octet. They are less important than CIDR today, but they still help with education, troubleshooting, and understanding older documentation.
6. Why are binary and hexadecimal outputs useful?
Binary helps explain subnetting and bit masks. Hexadecimal is useful in packet analysis, software tools, and low-level networking work where addresses may appear in compact hexadecimal format.
7. What happens with /31 and /32 networks?
These prefixes are handled specially. A /32 represents a single host. A /31 is commonly used on point-to-point links and effectively treats both addresses as usable endpoints.
8. Does this calculator support IPv6?
No. This page focuses on IPv4 decimal conversion only. IPv6 uses a different addressing structure, larger values, and different compression rules, so it requires a separate calculator.