ITCALCTOOLS.COM
// FREE IT TOOLS & CALCULATORS — 100+ TOOLS FOR TECH PROFESSIONALS
✓ 100% free
✓ No signup
✓ No paywalls
✓ Runs in your browser
// DEVELOPER
ASCII / UNICODE LOOKUP
Char codes, Unicode & HTML entities
BASE CONVERTER
Binary, Octal, Decimal, Hex
COLOR CODE CONVERTER
HEX, RGB, HSL converter
CRON EXPRESSION HELPER
Build & explain cron schedules
CSS SPECIFICITY CALC
Calculate CSS selector weight
HTTP HEADER REFERENCE
Common HTTP headers explained
HTTP STATUS CODES
All HTTP response codes
JSON FORMATTER
Validate, prettify, minify JSON
XML FORMATTER
Validate, prettify, minify XML
HTML FORMATTER
Validate, prettify, minify HTML
CSS FORMATTER
Validate, prettify, minify CSS
JS FORMATTER
Validate, prettify, compact JavaScript
LOREM IPSUM GENERATOR
Placeholder text generator
REGEX TESTER
Test regular expressions live
TEXT CASE CONVERTER
UPPER, lower, camelCase & more
UNIX TIMESTAMP CONVERTER
Epoch ↔ human readable date
URL ENCODER / DECODER
Encode & decode URLs
BASE64 ENCODER
Encode & decode Base64 strings
TEXT DIFF TOOL
Compare two blocks of text
HTML ENTITY ENCODER
Encode & decode HTML entities
YAML ↔ JSON CONVERTER
Convert between YAML and JSON
CRON NEXT-RUN CALCULATOR
Next 10 times a cron expression fires
CURL COMMAND BUILDER
Build a properly-escaped curl command
.GITIGNORE GENERATOR
Generate a .gitignore for your stack
JSON ↔ CSV CONVERTER
Convert between JSON arrays and CSV
JSON DIFF TOOL
Structural diff of two JSON documents
MARKDOWN PREVIEWER
Live-preview Markdown as you type
QR CODE GENERATOR
Generate a scannable QR code
SLUG GENERATOR
Turn a title into a URL-safe slug
SQL FORMATTER
Beautify minified SQL queries
TIMEZONE CONVERTER
Convert time across world timezones
WORD / CHARACTER COUNTER
Word, character & reading time counter
// HARDWARE
UPS BATTERY RUNTIME
Runtime from load & battery AH
CABLE LENGTH VS SPEED
Ethernet cable category guide
HEAT DISSIPATION CALC
BTU/hr & cooling requirements
MONITOR RESOLUTION
PPI & viewing distance calculator
PSU WATTAGE CALCULATOR
PC power supply requirements
RACK UNIT CALCULATOR
U space & weight capacity
FAN AIRFLOW / CFM CALC
Fan airflow from heat load
POE BUDGET CALCULATOR
PoE device power vs switch budget
// NETWORKING
BANDWIDTH CALCULATOR
Required bandwidth for users
CIDR REFERENCE TABLE
All CIDR /0–/32 prefixes
DNS LOOKUP
Query 12 global DNS resolvers
DNS RECORD TYPES
A, AAAA, MX, CNAME, TXT guide
IP CLASS FINDER
Identify IP class & type
MAC ADDRESS LOOKUP
OUI vendor from MAC address
EMAIL HEALTH CHECKER
SPF, DKIM, DMARC, MX checker
PING ESTIMATOR
Latency by distance & medium
PORT NUMBER REFERENCE
TCP/UDP port lookup
NETWORK SPEED CONVERTER
bps, Kbps, Mbps, Gbps converter
SSL CERTIFICATE CHECKER
TLS validity & SSL Labs grade
SUBNET CALCULATOR
IP/CIDR full subnet breakdown
VLSM CALCULATOR
Variable Length Subnet Masking
IP GEOLOCATION
Location & ISP from IP address
IP WHOIS LOOKUP
Who owns this IP? Block, registry & abuse contact
IPv4 TO IPv6 CONVERTER
Convert IPv4 addresses to IPv6
WHAT IS MY IP
Your public IP, ISP & location
NETWORK ADDRESS CALC
Bulk CIDR network address calc
REVERSE DNS LOOKUP
PTR record from IP address
WHOIS LOOKUP
Domain registration & ownership
TCP BANDWIDTH-DELAY PRODUCT
BDP & TCP window size calculator
CIDR AGGREGATOR
Find the smallest covering supernet
DHCP SCOPE CALCULATOR
DHCP pool size & utilization
IPV6 SUBNET CALCULATOR
Full subnet breakdown for IPv6
MTU / PATH MTU CALCULATOR
Effective MTU after VPN overhead
TTL / OS FINGERPRINT
Estimate hop count & OS from TTL
VLAN ID (802.1Q) REFERENCE
Look up any VLAN ID 0-4095
WAKE-ON-LAN PACKET BUILDER
Build a WoL magic packet
// SECURITY
CAESAR CIPHER
Encode/decode Caesar cipher
HASH GENERATOR
SHA-256, SHA-512, SHA-1 hashing
JWT DECODER
Decode & inspect JWT tokens
PASSWORD ENTROPY CALC
Bits of entropy calculator
PASSWORD GENERATOR
Cryptographically secure passwords
PASSWORD STRENGTH CHECKER
Entropy & crack time analysis
RANDOM TOKEN GENERATOR
UUID, hex token, API key gen
SSL EXPIRY CHECKER
Days until SSL cert expires
BCRYPT GENERATOR
Hash passwords with bcrypt
CSP HEADER BUILDER
Build Content Security Policy headers
TOTP / 2FA GENERATOR
Generate TOTP 2FA codes
AES ENCRYPT / DECRYPT
AES-256-GCM encrypt/decrypt with a passphrase
BASIC AUTH DECODER / ENCODER
Encode or decode a Basic Auth header
CVSS 3.1 SCORE CALCULATOR
Vulnerability severity score
EMAIL SPOOFABILITY CHECKER
Can someone forge email from this domain?
FILE CHECKSUM VERIFIER
Verify SHA-1/256/384/512 for a file
HMAC GENERATOR
Compute HMAC-SHA1/256/384/512
.HTPASSWD GENERATOR
Generate a bcrypt .htpasswd line
PASSWORD BREACH CHECKER
Check a password against known breaches
SECURITY.TXT GENERATOR
RFC 9116 security.txt builder
SRI HASH GENERATOR
Subresource Integrity hash generator
SSH KEY & CSR DECODER
SSH fingerprint & CSR subject decoder
// SERVER & CLOUD
CLOUD STORAGE COST EST.
S3, GCS, Azure cost estimator
DOCKER PORT REFERENCE
Common Docker exposed ports
IOPS CALCULATOR
Disk IOPS requirements
NETWORK LATENCY GUIDE
Acceptable latency by use case
UPTIME / SLA CALCULATOR
SLA downtime budget calculator
VM RESOURCE CALCULATOR
vCPU, RAM & storage for workload
CLOUD COMPUTE PRICING COMPARE
AWS, Azure, GCP compute cost estimator
KUBERNETES RESOURCE CALC
Suggested requests/limits YAML
LOG RETENTION COST CALCULATOR
Log storage cost from volume & retention
SERVERLESS COST ESTIMATOR
Lambda-style compute + request cost
// STORAGE
DATA RATE CONVERTER
Mbps, MB/s, Gbps, GB/s converter
RAID CALCULATOR
RAID 0/1/5/6/10 usable storage
STORAGE CONVERTER
KB, MB, GB, TB, PB, EB converter
TRANSFER TIME CALC
How long to transfer a file?
BACKUP ROTATION (GFS) CALC
GFS backup rotation storage calculator
COMPRESSION RATIO CALC
Compression ratio & space saved
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