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IP Range CalculatorPRO
Diagnostics, Generators & UtilitiesInstant Client-Side Tool

Batch Subnet Calculator

Calculate details for multiple prefixes.

Batch Subnet 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.
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How Batch Subnet Calculator Works?

This tool works by running the full subnet calculation on every line of a pasted prefix list and returning 1 result row per line.

  1. Paste a prefix list

    Enter up to thousands of prefixes, 1 per line, from a spreadsheet or export.

  2. Parse each line

    Each line is read as CIDR or address plus mask. Invalid lines are flagged and skipped.

  3. Calculate each prefix

    Every row receives network, broadcast, host range, mask, and host counts.

  4. Export the table

    The results download as CSV or JSON for spreadsheets and scripts.

Batch Subnet Calculator Formula

The formula applies Network = IP AND Mask, Broadcast = Network OR Wildcard, and Usable = 2^(32 − p) − 2 to each line independently.

Per-line network

N_i = IP_i AND Mask_i

Row i.

Per-line broadcast

B_i = N_i OR Wildcard_i

Row i.

Total addresses

Σ 2^(32 − p_i)

Sum across the batch.

Invalid lines

count(parse failures)

Reported, not calculated.

Worked example: 3-line batch

10.12.40.7/21     → 10.12.40.0 – 10.12.47.255  (2,046 hosts)
172.18.200.1/26   → 172.18.200.0 – 172.18.200.63  (62 hosts)
192.168.300.0/24  → invalid (octet above 255)

Batch Subnet Calculator Conversion Table

The table processes a batch of 9 prefixes and returns the main subnet values for each line.

InputNetworkBroadcastMaskFirst HostLast HostUsable
10.12.40.7/2110.12.40.010.12.47.255255.255.248.010.12.40.110.12.47.2542,046
172.18.200.1/26172.18.200.0172.18.200.63255.255.255.192172.18.200.1172.18.200.6262
192.168.77.9/24192.168.77.0192.168.77.255255.255.255.0192.168.77.1192.168.77.254254
10.200.3.3/3010.200.3.010.200.3.3255.255.255.25210.200.3.110.200.3.22
100.70.1.1/12100.64.0.0100.79.255.255255.240.0.0100.64.0.1100.79.255.2541,048,574
198.51.100.130/25198.51.100.128198.51.100.255255.255.255.128198.51.100.129198.51.100.254126
203.0.113.45/28203.0.113.32203.0.113.47255.255.255.240203.0.113.33203.0.113.4614
10.0.0.0/3110.0.0.010.0.0.1255.255.255.25410.0.0.010.0.0.12
192.0.2.99/32192.0.2.99192.0.2.99255.255.255.255192.0.2.99192.0.2.991

What is Batch Subnet Calculator?

The Batch Subnet Calculator is a tool that calculates subnet details for many prefixes at once and returns the results as a single table.

Audits, migrations, and documentation projects involve hundreds of subnets. Running a single-subnet calculator for each one is slow and error-prone. The batch calculator handles the full list in 1 pass and flags malformed lines.

Every row uses the same rules as the single IPv4 Subnet Calculator, including RFC 3021 handling of /31 links and host-route handling of /32 entries.

What are the uses of Batch Subnet Calculator?

There are 4 main uses of the Batch Subnet Calculator, including IPAM imports, audits, and documentation.

  • Preparing IPAM imports

    IPAM tools import subnets with network, mask, and gateway columns.

  • Auditing router configurations

    Interface prefixes from all routers are calculated together.

  • Documenting large estates

    One table documents every subnet at a site or region.

  • Cleaning spreadsheets

    Invalid lines in a shared spreadsheet are flagged in 1 run.