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IP Range CalculatorPRO
Masks, Wildcards & ACLInstant Client-Side Tool

IP Address and Mask Calculator

Calculate the corresponding network range.

IP Address and Mask Calculator: inputs and results

Enter an IP address, CIDR prefix, or range. Then check its first and last address below.

Quick presets:

Calculated Boundaries & ParametersReady

Network Address192.168.1.0
Broadcast Address192.168.1.255
First Usable Host192.168.1.1
Last Usable Host192.168.1.254
Subnet Mask255.255.255.0
Wildcard Mask0.0.0.255
Total Addresses256
Usable Host Range254

Key Capabilities

  • •100% Client-Side: Zero telemetry or server latency.
  • •RFC Compliant: Exact 32-bit and 128-bit integer precision.
  • •Quick Copy: Instant access to CIDR, mask, and range bounds.
  • •Cross-Platform: Works on desktop, tablet, and mobile browsers.
Open Full Interactive Suite

Related Masks, Wildcards & ACLAll Tools

CIDR to Subnet Mask Converter

Convert IPv4 prefixes to dotted masks.

Subnet Mask to CIDR Converter

Find prefix length from contiguous masks.

Subnet Mask Validator

Check mask structure and contiguity.

Subnet Mask to Wildcard Converter

Calculate the inverse IPv4 mask.

Wildcard Mask to Subnet Mask Converter

Convert compatible contiguous wildcard masks.

ACL Wildcard Match Calculator

Evaluate address-and-wildcard matching.

How IP Address and Mask Calculator Works?

This tool works by reading an address and a dotted-decimal subnet mask, converting the mask to a prefix length, and returning the network range that the pair defines.

  1. Enter the address

    Type an address such as 10.150.75.33.

  2. Enter the dotted mask

    Type the mask as shown on a device, for example 255.255.248.0.

  3. Convert the mask

    The calculator counts the 1 bits in the mask: 8 + 8 + 5 + 0 = 21, so the mask equals /21.

  4. Return the network range

    The calculator returns 10.150.72.0 – 10.150.79.255, a block of 2,048 addresses.

IP Address and Mask Calculator Formula

The formula is Range = [IP AND Mask, (IP AND Mask) OR (255.255.255.255 − Mask)].

Prefix from mask

p = count of 1 bits in Mask

255.255.248.0 → 21.

Range start

S = IP AND Mask

Per-octet AND.

Range end

E = S OR (255 − mask octet, per octet)

Per-octet inverse of the mask.

Range size

2^(32 − p)

2,048 addresses for /21.

Worked example: 10.150.75.33 255.255.248.0

Octet 3: 75 = 01001011, 248 = 11111000
75 AND 248 = 01001000 = 72
Start = 10.150.72.0
End   = 10.150.72.0 OR 0.0.7.255 = 10.150.79.255
Size  = 2^11 = 2,048

IP Address and Mask Calculator Conversion Table

The table pairs 10.150.75.33 with 11 dotted masks and shows the prefix, network range, and size of each pair.

Dotted MaskPrefixNetwork RangeSize
255.0.0.0/810.0.0.0 – 10.255.255.25516,777,216
255.240.0.0/1210.144.0.0 – 10.159.255.2551,048,576
255.255.0.0/1610.150.0.0 – 10.150.255.25565,536
255.255.192.0/1810.150.64.0 – 10.150.127.25516,384
255.255.240.0/2010.150.64.0 – 10.150.79.2554,096
255.255.248.0/2110.150.72.0 – 10.150.79.2552,048
255.255.252.0/2210.150.72.0 – 10.150.75.2551,024
255.255.255.0/2410.150.75.0 – 10.150.75.255256
255.255.255.192/2610.150.75.0 – 10.150.75.6364
255.255.255.240/2810.150.75.32 – 10.150.75.4716
255.255.255.248/2910.150.75.32 – 10.150.75.398

What is IP Address and Mask Calculator?

The IP Address and Mask Calculator is a tool that returns the network range defined by an IPv4 address paired with a dotted-decimal subnet mask.

Many devices display addressing as an address plus a dotted mask: Windows ipconfig, older Cisco IOS output, printers, and Internet of Things (IoT) devices. The IP Address and Mask Calculator accepts that exact format and needs no conversion to CIDR first.

The calculator validates the mask while it works. Masks with gaps between 1 bits, such as 255.255.0.255, are rejected, since no valid network range exists for them.

What are the uses of IP Address and Mask Calculator?

There are 4 main uses of the IP Address and Mask Calculator, including reading device output, help desk checks, and Windows configuration.

  • Reading ipconfig output

    Windows shows "Subnet Mask . . . : 255.255.248.0". The calculator turns the address and mask into a range.

  • Supporting help desk tickets

    Users read out an address and a mask. The calculator shows the network the device sits on.

  • Configuring embedded devices

    Cameras, printers, and IoT devices ask for a dotted mask. The calculator confirms the resulting range.

  • Comparing 2 device settings

    Two devices with the same mask and different ranges sit on different networks.