Enter a start IPv4 address and an end IPv4 address and this tool counts exactly how many addresses fall in the inclusive range between them. It converts each dotted decimal address to a 32 bit integer, subtracts, and adds one so both endpoints are counted, which is the correct way to size an allow list, a DHCP pool, or a block of addresses in a firewall rule. It also shows the two endpoints as their integer values so you can sanity check the ordering, and it warns you if the start address is greater than the end. Unlike CIDR based tools, this works for arbitrary ranges that do not line up on a power of two boundary, which is common in real allocations. All arithmetic runs locally in your browser using plain unsigned integer math, so no address you enter is ever sent to a server.
It converts both the start and end IPv4 addresses to 32-bit integers and returns the inclusive difference plus one, so both endpoints are counted.
No, you can enter any start and end address; the count works for arbitrary ranges, not just power of two blocks.
The addresses should be in order; put the lower address as the start and the higher one as the end to get a correct count.
Enter a start IPv4 address and an end IPv4 address and this tool counts exactly how many addresses fall in the inclusive range between them. It converts each dotted decimal address to a 32 bit integer, subtracts, and adds one so both endpoints are counted, which is the correct way to size an allow list, a DHCP pool, or a block of addresses in a firewall rule.
Yes. IPv4 Range Calculator is completely free, with no sign-up and no usage limits.
Yes. IPv4 Range Calculator runs in any modern web browser. There is nothing to download or install.
Yes. IPv4 Range Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.