Network
Free tools network
A network of 37+ free, browser-based calculators and utilities from the same team. Every tool runs client-side, with no signup and nothing stored on a server.
Solar, electrical & construction
voltdropcalc.com
Calculate voltage drop and the correct wire gauge for any DC or AC run across NEC, CEC, BS 7671, AS/NZS and IEC standards. The natural companion to this site for sizing the cables, fuses and runs in a solar install so you do not lose power or overheat conductors.
prosolarcalc.tools
A set of professional solar sizing and design tools for installers and serious DIY builders, covering the calculations that go into planning a photovoltaic system from panels through to storage.
actonnagecalc.com
Work out the air-conditioner tonnage and cooling load a room or whole home needs, based on area, climate, insulation and sun exposure, so you neither undersize the unit nor waste money oversizing it.
cubicyardage.com
Concrete and bulk-material calculators that work the way contractors do, in cubic yards, for slabs, footings, columns, walls and stairs, with bag counts, ready-mix loads and a waste margin built in.
thesquarefootagecalculator.com
Measure square footage for floors, walls, rooms and land across many shapes including rectangles, triangles, circles and irregular layouts, with unit conversion handled for you.
boxvolumecalculator.com
Calculate the volume and capacity of boxes, cartons and rectangular containers in any units, useful for packing, shipping and storage planning.
tankvolumecalc.com
Find the volume and fill level of tanks in many shapes, cylindrical, oval, rectangular and capsule, horizontal or vertical, for water, fuel and chemical storage.
dimweightcalc.com
Compute dimensional (volumetric) weight for FedEx, UPS, USPS and other carriers and compare it against actual weight, so you can predict shipping charges before you ship.
girthcalculator.com
Measure a package's girth and combined length-plus-girth and check it against carrier oversize limits before you pay for shipping.
Finance & business
totalinterestcalc.com
See the full lifetime cost of a mortgage or loan, the total interest paid, the amortization schedule and the effect of extra payments, so you understand what borrowing really costs.
indiaemi.com
An EMI calculator built for India, covering home, car and personal loans plus credit-card EMI plans with GST, and the difference between EMI in advance and in arrears.
marginvsmarkup.com
Convert between margin and markup and price products correctly, clearing up the common confusion between the two that quietly erodes profit.
bestpercentagecalculator.net
Handle every kind of everyday percentage problem, percentage of a number, percentage change, increase, decrease and reverse percentages, in one clear tool.
Developer & web utilities
jsontools.tools
Format, validate, minify and explore JSON in your browser, with a tree viewer that makes large or messy payloads easy to read and debug.
base64decode.tools
Encode text and files to Base64 or decode them back, entirely client-side so nothing you paste ever leaves your machine.
urlencodedecode.com
Percent-encode and decode URLs and query strings so special characters are transmitted safely, with full Unicode support.
hashgenerator.tools
Generate MD5, SHA-1, SHA-256 and other cryptographic hashes from text or files for checksums, integrity checks and fingerprinting.
uuidcore.com
Generate UUIDs in bulk and learn how the different versions work, with copy-ready output for development and testing.
regexguide.com
Build, test and understand regular expressions with live matching and a reference that explains each token in plain language.
crontabsheet.com
Build cron schedules visually and read back exactly when a crontab expression will run, with a cheat sheet of common patterns.
epochtime.tools
Convert between Unix epoch timestamps and human-readable dates in any time zone, in seconds or milliseconds, in both directions.
cidrcalculator.net
Work out network and broadcast addresses, host ranges and subnet sizes from CIDR notation, with clear breakdowns for network planning.
subnetmaskcalc.net
Calculate subnet masks, host counts and address ranges, with worked examples and code snippets in several languages for network engineers.
barcodeandqr.com
Generate barcodes and QR codes in many formats and export them print-ready as PNG or PDF, all rendered locally in your browser.
removemetadata.tools
Strip hidden metadata, EXIF, location, author and more, from images, PDFs, Office files, audio and video entirely in your browser, so nothing is ever uploaded.
corepdftools.com
Merge, split, compress, rotate and password-protect PDF files client-side, keeping your documents private because they never leave your device.
colorcodekit.com
Convert color codes between HEX, RGB, HSL and more, build palettes and gradients, and export tokens for SwiftUI, Flutter and Jetpack Compose.
pictoolkit.com
A toolkit of browser-based image utilities for resizing, converting and editing pictures without uploading them anywhere.
Text & time
wordcounterfree.com
Count words, characters, sentences and paragraphs and estimate reading time as you type, useful for essays, articles and content limits.
transformcase.com
Convert text between upper case, lower case, title case, sentence case and more in one click, handy for cleaning up copy and code.
textrepeat.net
Repeat, duplicate and generate blocks of text quickly, with control over separators and counts for testing and formatting.
unitcheatsheet.com
A fast reference and converter for units of length, weight, volume, temperature and more, with the common conversions you actually look up.
calculatehours.net
Add up the hours between start and end times, including overnight spans and breaks, useful for timesheets, shifts and payroll.
clockwithus.com
Check the current time across world cities and time zones at a glance, for scheduling calls and coordinating across regions.
theagecalculator.net
Calculate exact age in years, months and days, plus milestones, birthday countdowns and age comparisons between people.
passwordstrength.net
Test how strong a password is and how long it would take to crack, with practical guidance on building passwords that resist attacks, checked locally and never sent anywhere.
Health
These are sites in our own network, linked openly with rel="nofollow noopener". We link them because they are built to the same standard, not as paid placements.