Question 1

What is CIDR?

Accepted Answer

CIDR (Classless Inter-Domain Routing) notation uses /prefix to indicate network bits, e.g. /24 = 255.255.255.0.

Question 2

What are usable hosts?

Accepted Answer

Total IPs minus 2 (network + broadcast addresses). A /30 gives 2 usable hosts.

Question 3

How do I use this Subnet Calculator online free?

Accepted Answer

Enter your numbers above and get instant results. Free with no login, works on mobile and desktop.

Question 4

Is this Subnet Calculator accurate?

Accepted Answer

Yes. The Subnet Calculator uses standard formulas and 2026 rules. Always verify big decisions with a professional.

Question 5

What do I need to enter?

Accepted Answer

Just fill the fields above and results update live. No sign-up, free on any device.

Question 6

Is this Subnet Calculator free?

Accepted Answer

Yes, completely free with no sign-up. Use it unlimited times online on any device.