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Address integer = octets packed into 32 bits. Mask = first prefix bits set to 1. Network = address AND mask. Broadcast = network OR inverted mask. Usable hosts = 2^(32 − prefix) − 2 for ordinary prefixes.
Apply the formulaAddress integer = octets packed into 32 bits. Mask = first prefix bits set to 1. Network = address AND mask. Broadcast = network OR inverted mask. Usable hosts = 2^(32 − prefix) − 2 for ordinary prefixes.192.168.10.0/24Mask 255.255.255.0 · wildcard 0.0.0.255 · broadcast 192.168.10.255 · usable range 192.168.10.1 to 192.168.10.254 · 254 usable host address(es)
Your live breakdown
Current inputs in the calculation
These values come from the controls above and update when the calculator changes.
IP octet 1
192
First IPv4 octet.
IP octet 2
168
Second IPv4 octet.
IP octet 3
10
Third IPv4 octet.
IP octet 4
25
Fourth IPv4 octet.
CIDR prefix
24 /n
Use 24 for a common 255.255.255.0 network.
Resulting answer
192.168.10.0/24
Mask 255.255.255.0 · wildcard 0.0.0.255 · broadcast 192.168.10.255 · usable range 192.168.10.1 to 192.168.10.254 · 254 usable host address(es)
Answer
192.168.10.0/24
Live support
Mask 255.255.255.0 · wildcard 0.0.0.255 · broadcast 192.168.10.255 · usable range 192.168.10.1 to 192.168.10.254 · 254 usable host address(es)
Assumptions used
What this answer assumes
Best for quick CIDR checks, network documentation and ACL planning notes.
IPv4 only; IPv6 is not modelled.
/31 and /32 networks have special point-to-point or host-route behaviour, so usable host notes differ.
Routing policy, VLANs, NAT, DHCP scopes and firewall rules are outside the arithmetic.
Master’s Tip
How to use the result well
Master’s Tip: print the wildcard mask beside the subnet mask when handing a network note to someone writing ACLs.
Printable record
What belongs in the saved calculation
Save the inputs, result, formula, assumptions, page URL and date together so the calculation can be reviewed later.
IP octet 1
192
First IPv4 octet.
IP octet 2
168
Second IPv4 octet.
IP octet 3
10
Third IPv4 octet.
IP octet 4
25
Fourth IPv4 octet.
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Formula
Address integer = octets packed into 32 bits. Mask = first prefix bits set to 1. Network = address AND mask. Broadcast = network OR inverted mask. Usable hosts = 2^(32 − prefix) − 2 for ordinary prefixes.
Worked example
192.168.10.25/24 has mask 255.255.255.0, network 192.168.10.0, broadcast 192.168.10.255 and ordinary usable host range 192.168.10.1 to 192.168.10.254.
Professional note
Master’s Tip: print the wildcard mask beside the subnet mask when handing a network note to someone writing ACLs.
Regional and unit assumptions
Standard IPv4 CIDR arithmetic using 32-bit addresses and binary masks.
Assumptions and limitations
IPv4 only; IPv6 is not modelled.
/31 and /32 networks have special point-to-point or host-route behaviour, so usable host notes differ.
Routing policy, VLANs, NAT, DHCP scopes and firewall rules are outside the arithmetic.
Methodology & Accuracy
How this calculator is checked
CalculationTime pages are built around visible arithmetic: the formula, assumptions, worked example and practical limitations are shown so the result can be checked rather than simply trusted.
Formula used
Address integer = octets packed into 32 bits. Mask = first prefix bits set to 1. Network = address AND mask. Broadcast = network OR inverted mask. Usable hosts = 2^(32 − prefix) − 2 for ordinary prefixes.
Standard or basis
Standard IPv4 CIDR arithmetic using 32-bit addresses and binary masks.
Where a calculator follows a named legal, trade or industry standard, that standard is cited visibly. Otherwise the page uses transparent general arithmetic and states its limits.
Master's Tip
Master’s Tip: print the wildcard mask beside the subnet mask when handing a network note to someone writing ACLs.
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