CIDR is the short for Classless Inter-Domain Routing, an IP addressing scheme that replaces the older system based on classes A, B, and C. A single IP address can be used to designate many unique IP addresses with CIDR. A CIDR IP address looks like a normal IP address except that it ends with a slash followed by a number, called the IP network prefix. CIDR addresses reduce the size of routing tables and make more IP addresses available within organizations.


CIDR to IP range

This tool converts CIDR to IP range.


IP Range to CIDR

This tool converts IP range to CIDR.



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CIDR calculator
CIDR Calculator

Add this to your web site by copy the following HTML code and place it in your web page.


<form action="" method="post">
<p style="background:#fff;border:1px solid #99A8AE;width:180px;padding:5px 5px 5px 5px;font-size:11px;font-family:'Trebuchet MS',Arial,Sans-serif;">
	<a href="" target="_blank"><img src="" alt="CIDR calculator" border="0" width="120" height="12" /></a><br />
	<b>CIDR Calculator</b><br /><br />
	<label>CIDR</label> <input type="text" name="cidr" value="" style="border:solid 1px #C0C0C0;font-size:9px;width:110px;" /><br />
	<input type="submit" value="Calculate" style="width:100px;font-size:10px;margin-top:3px;padding:2px 3px;color:#FFF;background:#8EB50C;border-width:1px;border-style:solid;">

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