> Give it a block and what you need. It lays out the subnets, in order, with nothing overlapping.

# Subnet Master

Give it a block and what you need. It lays out the subnets, in order, with nothing overlapping.

$2.99 · lifetime · One payment. No subscription.

5.0 from 1 rating

## See it in action

![Ask in hosts. 500, 120, 60 and 2 come back as a /23, a /25, a /26 and a /30.](https://evlarsoft.com/apps/subnet-master/s4.jpg)

Ask in hosts. 500, 120, 60 and 2 come back as a /23, a /25, a /26 and a /30.

![What is left, as aligned CIDR blocks you can actually assign — not a count of spare addresses.](https://evlarsoft.com/apps/subnet-master/s3.jpg)

What is left, as aligned CIDR blocks you can actually assign — not a count of spare addresses.

![Or just cut it in four. Ask for six and it says eight, and says why.](https://evlarsoft.com/apps/subnet-master/s1.jpg)

Or just cut it in four. Ask for six and it says eight, and says why.

![Copy all writes a table a spreadsheet and a change request both accept.](https://evlarsoft.com/apps/subnet-master/s5.jpg)

Copy all writes a table a spreadsheet and a change request both accept.

## About Subnet Master

Subnet Master divides a block. Not describes one — divides it.

Give it 10.0.0.0/16 and say how you want it cut. Either answer arrives while you type, and every network it lays out starts on its own boundary, in order, with nothing overlapping.

## Two ways to cut it

Equal parts is the simple one: type a number and get that many subnets. Ask for six and it gives you eight, and tells you why — a prefix can only halve, so there is no such thing as a sixth of a block.

By host counts is the one a fixed split cannot answer. List what you need — Sales 500, Engineering 120, Guest Wi-Fi 60, a point-to-point link — and it sizes each one and packs them. Largest first, because that is what makes them fit: allocate a big network after a small one and the big one can no longer start where it must.

## And what is left

Most calculators stop at a number of spare addresses, which is not something you can hand to anyone. This one gives the remainder back as whole CIDR blocks — a /30, a /29, a /28, a /27 and a /24 — because a range that does not start on its own boundary is not a subnet and cannot be assigned.

## It shows you the cost

Every row carries the spare: 500 hosts in a /23 leaves ten addresses doing nothing. A utilization bar shows how much of the block the plan consumes. Anything that will not fit is named, not silently dropped.

## Out of the app

Copy one subnet, or copy the whole plan as a tab-separated table — network, netmask, first host, last host, broadcast, usable — that a spreadsheet and a change request both accept.

It follows your Windows theme, has no account, no sign-in and no ads, and it never opens a socket, because there is nothing here it would need the network for.

Built for Windows 11, and at home on Windows 10.

## Features

-   Divide a block into equal parts, or into networks of the sizes you actually need
-   VLSM: ask for 500, 120, 60 and 2 hosts and get a /23, a /25, a /26 and a /30
-   Allocated largest first, so every network lands on its own boundary with no gaps
-   Says what is left as aligned CIDR blocks you can assign, not a count of spare addresses
-   Shows the spare in each network, so an oversized prefix is visible before it ships
-   Names what will not fit rather than dropping it quietly
-   A utilization bar for how much of the block the plan consumes
-   Copy any subnet, or the whole plan as a table a spreadsheet accepts
-   Correct on /31 point-to-point links, which most planners are not
-   No account, no ads, and it does all its math on your PC

## Details

Works on

Windows 10 (1809 or later) and Windows 11

Download

About 2.3 MB

Version

2.0.5, updated October 2026

First released

June 2023

Price

$2.99, lifetime license. No subscription.

Category

Utilities & tools

## Questions

Anything else? [Ask us](https://evlarsoft.com/contact?topic=support&app=Subnet%20Master)

### Which versions of Windows does it run on?

Windows 10 (version 1809 or later) and Windows 11.

### Is it a subscription?

No. Subnet Master is a one-time purchase of $2.99, and updates are included.

### How do I get it?

EvlarSoft apps are moving to direct downloads from this site. Ask to be notified and we will email you as soon as Subnet Master is ready to download.

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Source: https://evlarsoft.com/apps/subnet-master