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About TCP UDP Port Range Calculator – Port Counting & Classification
Calculate the inclusive count of port numbers across any span within the 16-bit transport layer address space (0 to 65535).
Identify whether your selected port range lies within or crosses standard IANA system, registered, or dynamic/ephemeral port bands.
Input is processed locally in your browser and is not sent to Navorika.
How the calculation works
Inclusive port count
Port count = End Port − Start Port + 1 (when start ≤ end).
System / Well-Known band
Ports 0 through 1023, traditionally reserved for privileged system services.
User / Registered band
Ports 1024 through 49151, assigned by IANA for specific vendor applications and services.
Dynamic / Private band
Ports 49152 through 65535, used for outbound ephemeral client connections and private custom services.
How to use this tool
- 1Enter the starting integer port number between 0 and 65535.
- 2Enter the ending integer port number between 0 and 65535.
- 3Review the total inclusive port count for firewall rule planning.
- 4Check whether the range crosses standard port classification boundaries.
- 5Export the summary or download the port breakdown as a CSV.
Understanding the result
Ranges that cross from 0–1023 into 1024–49151 span both system and registered port bands, which often require distinct firewall policies.
Dynamic ports (49152–65535) are commonly used as source ports for client connections and rarely need inbound firewall openings.
Both TCP and UDP utilize the same 16-bit numbering space independently, meaning port 443 TCP and port 443 UDP are separate endpoints.
Important limitations
- This tool calculates numeric port values; it does not test whether ports are open, blocked, or filtered on a host.
- TCP and UDP protocol stacks operate separately on the same numeric port.
- Numeric categorization reflects IANA recommendations, but applications can bind to non-standard ports.
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Frequently asked questions
Why are there 65,536 possible ports in TCP and UDP?
The TCP and UDP packet headers allocate a 16-bit field for both source and destination port numbers (2^16 = 65,536 possible values, from 0 to 65535).
What is the difference between TCP and UDP ports?
TCP is connection-oriented with acknowledgments, while UDP is connectionless. They use the same numerical port range independently on any given network interface.
What are ephemeral ports?
Ephemeral ports (typically 49152–65535) are temporary port numbers automatically assigned by the client operating system for outgoing requests.
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