# IT, networking & security calculators

> IT calculators for IP subnets, bandwidth and download time, storage units, RAID capacity, uptime and password strength.

Page: https://calculators.geekmidst.com/categories/it-networking

- [Data Transfer Time Calculator](https://calculators.geekmidst.com/calculators/data-transfer-time-calculator.md): Work out how long it takes to transfer data of any size (kB to TB, KiB to TiB) over a link in kbps, Mbps, Gbps or MB/s, with an efficiency allowance.
- [IP Subnet Calculator](https://calculators.geekmidst.com/calculators/ip-subnet-calculator.md): Enter an IPv4 address and prefix length (CIDR) to get the network and broadcast addresses, subnet mask, wildcard mask and usable host range.
- [Password Generator](https://calculators.geekmidst.com/calculators/password-generator.md): Generate a random password in your browser with the length and character types you choose, and see its strength in bits of entropy.
- [Website Bandwidth Calculator](https://calculators.geekmidst.com/calculators/bandwidth-calculator.md): Estimate a website’s monthly data transfer in GB from page views and page size, and the average and recommended bandwidth in Mbps.
- [Base64 Encoder and Decoder](https://calculators.geekmidst.com/calculators/base64-encoder-decoder.md): Encode text to Base64 or decode Base64 back to text, using UTF-8, with standard or URL-safe alphabets as defined in RFC 4648.
- [URL Encoder and Decoder](https://calculators.geekmidst.com/calculators/url-encoder-decoder.md): Percent-encode text for use in a URL query or path, or decode %XX sequences back to readable text, with UTF-8 and form (+ for space) modes.
- [IPv4 Range to CIDR Calculator](https://calculators.geekmidst.com/calculators/ipv4-cidr-range-calculator.md): Turn a first and last IPv4 address into the smallest exact list of CIDR blocks, for firewall rules, ACLs, allow-lists and route tables.
- [IPv6 Prefix Calculator](https://calculators.geekmidst.com/calculators/ipv6-prefix-calculator.md): Enter an IPv6 address and prefix length to get the exact number of addresses, the first and last address, and how many /64 (or other) subnets fit.
- [VLSM Subnet Calculator](https://calculators.geekmidst.com/calculators/vlsm-subnet-calculator.md): Split an IPv4 network into right-sized subnets for each host requirement, largest first, with masks, usable ranges, broadcasts and space left over.
- [Network Throughput Calculator](https://calculators.geekmidst.com/calculators/network-throughput-calculator.md): Work out the real throughput of a transfer from the data moved and the time it took, in Mbps, Gbps, MB/s and MiB/s, and compare it with your link speed.
- [Packet Loss Calculator](https://calculators.geekmidst.com/calculators/packet-loss-calculator.md): Calculate packet loss as a percentage of packets sent, plus the number lost and the delivery rate, from ping, iperf or interface counters.
- [Network Latency (RTT) Calculator](https://calculators.geekmidst.com/calculators/network-latency-rtt-calculator.md): Estimate one-way latency and round-trip time from path length, fibre or radio propagation, packet serialisation and per-hop delay.
- [TCP Bandwidth-Delay Product Calculator](https://calculators.geekmidst.com/calculators/tcp-bandwidth-delay-product-calculator.md): Find the bandwidth-delay product of a path in bytes, the TCP window scale it needs, and the maximum throughput a given receive window allows.
- [DNS TTL Cache Window Calculator](https://calculators.geekmidst.com/calculators/dns-ttl-cache-window-calculator.md): Plan a DNS cut-over: how long before the change to lower the TTL, how long old answers can stay cached afterwards, and the extra lookup load.
- [TLS Certificate Expiry Calculator](https://calculators.geekmidst.com/calculators/tls-certificate-expiry-calculator.md): Work out when a TLS/SSL certificate expires from its issue date and validity, how many days are left, and the date to renew with your chosen lead time.
- [Password Entropy Calculator](https://calculators.geekmidst.com/calculators/password-entropy-calculator.md): Calculate the entropy in bits of a randomly generated password or Diceware-style passphrase from its length and the size of the character set or word list.
- [Password Brute-Force Time Calculator](https://calculators.geekmidst.com/calculators/password-brute-force-time-calculator.md): Estimate how long an exhaustive search would take to find a random password or passphrase, on average and in the worst case, at a guess rate you choose.
- [PBKDF2 Runtime Calculator](https://calculators.geekmidst.com/calculators/pbkdf2-runtime-calculator.md): Estimate how long one PBKDF2 key derivation takes on your server from the iteration count and your measured HMAC rate, and how far it slows an attacker.
- [RAID Capacity Calculator](https://calculators.geekmidst.com/calculators/raid-capacity-calculator.md): Work out usable storage for RAID 0, 1, 5, 6 and 10 from the number and size of drives, in decimal TB and binary TiB, with fault tolerance and efficiency.
- [RAID Rebuild Time Calculator](https://calculators.geekmidst.com/calculators/raid-rebuild-time-calculator.md): Estimate how long a RAID array takes to rebuild onto a replacement drive from its capacity, the rebuild rate in MB/s and how much of it must be rewritten.
- [Database Backup Window Calculator](https://calculators.geekmidst.com/calculators/database-backup-window-calculator.md): Estimate how long a full database backup takes from its size, read and write throughput and compression, and whether it fits your backup window.
- [Download Time Calculator](https://calculators.geekmidst.com/calculators/download-time-calculator.md): Work out how long a file takes to download or upload from its size in MB, GB or GiB and your speed in Mbps or MB/s, with protocol overhead.
- [Wi-Fi Channel Capacity Calculator](https://calculators.geekmidst.com/calculators/wifi-channel-capacity-calculator.md): Calculate the Wi-Fi 5 or Wi-Fi 6 PHY data rate from channel width, MCS, spatial streams and guard interval, then estimate usable throughput per client.
- [Free-Space Path Loss Calculator](https://calculators.geekmidst.com/calculators/free-space-path-loss-calculator.md): Calculate free-space path loss in dB from distance and frequency, and the received signal in dBm from transmit power and antenna gains, for Wi-Fi and radio links.
- [Firewall Rule Coverage Calculator](https://calculators.geekmidst.com/calculators/firewall-rule-coverage-calculator.md): Measure firewall rule-base hygiene: the share of rules that matched traffic in a review period, unused rules to review and shadowed rules to remove.
- [Cybersecurity Risk Score Calculator](https://calculators.geekmidst.com/calculators/cybersecurity-risk-score-calculator.md): Combine your own risk factors, scores and weights into a transparent 0–100 cybersecurity risk index and see which factor contributes most.
- [Security Patch Compliance Calculator](https://calculators.geekmidst.com/calculators/security-patch-compliance-calculator.md): Work out the share of in-scope assets patched within your SLA, excluding approved exceptions, and how many more must be fixed to hit your target.
- [Phishing Simulation Rate Calculator](https://calculators.geekmidst.com/calculators/phishing-simulation-rate-calculator.md): Turn phishing-test results into click rate, credential submission rate and report rate, all measured against delivered emails, plus reports per click.
- [Mean Time to Detect (MTTD) Calculator](https://calculators.geekmidst.com/calculators/incident-mean-time-to-detect-calculator.md): Paste when each incident started and when it was detected to get mean time to detect, plus the median, 90th percentile and longest detection time.
- [Mean Time to Respond Calculator](https://calculators.geekmidst.com/calculators/incident-mean-time-to-respond-calculator.md): Enter detection and response timestamps for each incident to get the mean time to respond, with the median, 90th percentile and slowest response.
- [Mean Time to Recover (MTTR) Calculator](https://calculators.geekmidst.com/calculators/incident-mean-time-to-recover-calculator.md): Paste when each outage or incident began and when service was restored to get mean time to recover, with the median, 90th percentile and longest outage.
- [Availability Percentage Calculator](https://calculators.geekmidst.com/calculators/availability-percentage-calculator.md): Measure availability from actual downtime over a period, or from MTBF and MTTR, and see the number of nines and the downtime that rate implies per year.
- [Storage IOPS Requirement Calculator](https://calculators.geekmidst.com/calculators/storage-iops-requirement-calculator.md): Convert workload IOPS and read/write mix into back-end IOPS with the RAID write penalty, and find how many drives meet it with your chosen headroom.
- [Log Retention Storage Calculator](https://calculators.geekmidst.com/calculators/log-retention-storage-calculator.md): Estimate log storage for a retention period from events per second and event size, or daily GB, with compression, index overhead and replica copies.
- [SIEM Ingest Cost Calculator](https://calculators.geekmidst.com/calculators/siem-ingest-cost-calculator.md): Estimate monthly and annual SIEM or log-analytics ingest cost from GB per day and your per-GB price, with a free daily allowance and fixed fees.
- [VPN Bandwidth Estimate Calculator](https://calculators.geekmidst.com/calculators/vpn-bandwidth-estimate-calculator.md): Estimate the VPN gateway bandwidth you need from remote users, peak concurrency, traffic per user, packet size, per-packet tunnel overhead and headroom.
- [Cloud Egress Cost Calculator](https://calculators.geekmidst.com/calculators/cloud-egress-cost-calculator.md): Work out the monthly cost of data transferred out of a cloud provider with a free allowance and tiered per-GB prices that you enter from your provider’s price list.
- [Network Packet Overhead Calculator](https://calculators.geekmidst.com/calculators/network-packet-overhead-calculator.md): See how many packets and bytes on the wire it takes to send data over Ethernet with IPv4 or IPv6 and TCP or UDP, and the resulting protocol efficiency.
- [IPv4 to Integer Converter](https://calculators.geekmidst.com/calculators/ipv4-to-integer-converter.md): Convert a dotted IPv4 address to its 32-bit integer, hexadecimal and binary forms, or turn an integer back into a dotted-quad IP address.
- [IPv6 Address Compression Calculator](https://calculators.geekmidst.com/calculators/ipv6-address-compression-calculator.md): Shorten any IPv6 address to its canonical RFC 5952 form, or expand it to all eight full groups, and see what type of address it is.
- [UTF-8 Byte Length Calculator](https://calculators.geekmidst.com/calculators/utf8-byte-length-calculator.md): Count how many bytes text takes in UTF-8, alongside code points, UTF-16 units and bytes, and check it against a byte limit such as a database column.
- [SHA-256 Checksum Calculator](https://calculators.geekmidst.com/calculators/sha256-checksum-calculator.md): Compute the SHA-256 hash of text (UTF-8) or raw hex bytes in your browser, and compare it with an expected checksum.
- [Unix Epoch Converter](https://calculators.geekmidst.com/calculators/unix-epoch-converter.md): Convert a Unix timestamp in seconds or milliseconds to a UTC and local date, or a date and time with a UTC offset to epoch seconds, with ISO 8601 output.
- [Cron Next Occurrence Calculator](https://calculators.geekmidst.com/calculators/cron-next-occurrence-calculator.md): Enter a five-field cron expression and a start time to list its next run times, with ranges, steps, names, @daily-style macros and the day-of-month/day-of-week rule.