IT Calculators
Conversions, network, storage, performance and developer tools.
Conversions and formats
ASCII / Unicode
Character code point (decimal, hex).
Use calculator →Base64 size
Size increase when encoding to Base64.
Use calculator →Binary / Hex / Decimal
Number converter: binary, octal, hex, decimal.
Use calculator →Checksum
Simple checksum (mod 256/65536).
Use calculator →Cron schedule
How many times a cron job runs in a period.
Use calculator →Duration
Time in seconds from notation like 1h 30m 45s.
Use calculator →Hash collisions
Birthday problem: collisions for n items and b bits.
Use calculator →Hex to RGB
Convert hex and RGB colours.
Use calculator →Memory units
Convert KB, MB, GB, TB, KiB, MiB.
Use calculator →Pixel to rem
Convert pixels to rem/em (CSS).
Use calculator →Timezone converter
Convert between IANA time zones: enter a date and wall-clock time in the source zone; see the same instant in the target zone, optional extra zones, and UTC. DST is handled by your browser (Intl).
Use calculator →Unix timestamp
Timestamp ↔ date: seconds or milliseconds, UTC ISO, local time, one-click copy.
Use calculator →URL encode
URL encoding and decoding (percent-encoding).
Use calculator →Network
DHCP range
Number of host addresses in the DHCP pool for a given CIDR mask (/8\u2013/32). Network and broadcast addresses are excluded (minus 2).
Use calculator →DNS TTL
DNS record TTL in seconds.
Use calculator →IP subnet
IPv4 subnet calculator: address, mask, range.
Use calculator →IPv6 shorthand
Short IPv6 notation.
Use calculator →Latency vs distance
Minimum RTT for distance (fibre).
Use calculator →MTU and IP fragmentation
Number of IP fragments for a given MTU.
Use calculator →Storage and performance
Autoscaling (POD)
Min–max interpolation: estimated pods at a scale level (%).
Use calculator →Backup window
Time needed for backup at given throughput.
Use calculator →Bandwidth cost
Data transfer (egress) cost.
Use calculator →Bundle size
Estimated size after minification/gzip.
Use calculator →Cache hit ratio
Effect of hit ratio on backend load.
Use calculator →Cloud cost
Estimated monthly storage cost (GB).
Use calculator →Compression ratio
Compression level (size before/after).
Use calculator →Data transfer time
Time to transfer data at a given throughput.
Use calculator →Database connections
Number of connections per thread/instance.
Use calculator →File download time
Download time for file size and link speed.
Use calculator →IOPS
Estimate IOPS and MB/s from response time.
Use calculator →JSON size
Approximate size in bytes (chars + overhead).
Use calculator →JWT token
Estimated JWT token size (Base64).
Use calculator →Log storage
Estimate disk space for logs: size per entry × number of entries × period. Consider rotation (e.g. logrotate) and compression (gzip).
Use calculator →PC power supply
Estimated power supply requirement (W).
Use calculator →Percentiles
Interpretation of latency percentiles.
Use calculator →Queue depth
Queue depth and latency.
Use calculator →RAID capacity
Usable capacity for RAID 0, 1, 5, 6, 10, 50, 60.
Use calculator →Replication lag
Replication delay.
Use calculator →Resolution and PPI
Screen PPI/DPI and pixel size.
Use calculator →Storage cost
Monthly cloud disk cost.
Use calculator →Throughput (MB/s)
MB/s for 4K/64K block size.
Use calculator →Uptime and downtime
Convert uptime percentage (e.g. 99.9% \u2014 "three nines") to allowable downtime in minutes per year and per month. Useful for SLAs and availability targets.
Use calculator →Other
API rate limit
Calculate requests in a period and minimum interval between requests for a given limit (requests per minute) and window length. Throttling and HTTP 429.
Use calculator →Cost per request
Cost per 1k/1M requests.
Use calculator →Deploy frequency
Deploys per day/week from interval.
Use calculator →Error budget
Allowed downtime for a given SLO (e.g. 99.9%). Error budget = 1 − SLO; spending the budget affects rollout pace in SRE.
Use calculator →MTTR
Mean time to repair and between failures.
Use calculator →Password entropy
Password strength and entropy in bits.
Use calculator →Retry backoff
Delays between retries.
Use calculator →ROI: cloud vs on-premise
Cost comparison over time: cloud vs on-premise.
Use calculator →SSL certificate expiry
Days until SSL certificate expires.
Use calculator →SSL expiration
Check how many days, weeks and months remain until your SSL/TLS certificate expires (notAfter). The calculator shows validity status and the recommended renewal window.
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