Network
Free tools network
A network of 52+ 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.com
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.
backuppowercalc.com
Size a generator or battery backup from the combined wattage of the appliances you need to run and how long you need them, so you plan for outages without over- or under-buying capacity.
staircalculators.net
Work out stair rise, run, stringer length and the number of steps to meet building-code comfort and safety limits, so you can plan a safe, comfortable staircase before any timber is cut.
concretematerialcalc.com
Estimate the concrete, cement, sand and aggregate needed for slabs, footings, columns and paths, with the right mix ratio, so you can plan a pour and buy the correct number of bags.
roofingmaterialcalc.com
Estimate shingles, underlayment and other materials from your roof's area and pitch, with waste factored in, so you can budget a re-roof accurately and reduce leftover bundles.
constructioncalchq.com
A hub of construction calculators covering materials, areas, volumes and project estimates in one place, for the everyday jobsite math that builders and serious DIYers reach for repeatedly.
poolvolumecalc.com
Find the water volume of a swimming pool in gallons or litres for rectangular, round, oval and irregular shapes and depths, the number behind dosing chemicals, sizing a heater and estimating refills.
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.
sipcalculatorhub.com
Project the maturity value of a mutual-fund SIP from your monthly contribution, expected return and tenure, with optional annual step-ups, showing how compounding builds the corpus year by year.
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.
checkinternetspeed.tools
Measure your download, upload and ping speed straight in the browser, with a clear read on latency and throughput, a fast way to check whether a connection is performing as it should.
checkmyipnow.com
See your public IP address along with the location, ISP and browser details any website can detect, handy for troubleshooting connections, confirming a VPN and setting up remote access.
whoislookuppro.com
Look up domain registration, ownership, expiry dates and DNS records for any website, useful for buying domains, tracking your own renewals and researching who is behind a site.
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.
measurechef.com
Convert cups, grams, ounces, millilitres, tablespoons and teaspoons for any recipe, ingredient by ingredient, so you can scale servings up or down and switch between metric and imperial.
fractionsteps.com
Add, subtract, multiply and divide fractions and mixed numbers with every step of the working shown, built for homework, recipes and workshop measurements that refuse to become tidy decimals.
gpacalculatorhq.com
Work out grade point average and cumulative CGPA from letter grades and credit hours across common scales, so you can track where you stand and the marks you still need for a target.
numtotext.com
Convert numbers into their written-out words for cheques, invoices, contracts and legal documents, handling currency formatting and very large figures so the words always match the digits.
Health
calorieskit.com
A suite of calorie, macronutrient and body-composition calculators, daily calorie needs, protein targets, lean body mass and more, with clear methodology behind every number.
bmibmrcalc.com
Calculate body mass index and basal metabolic rate from height, weight, age and sex, showing where you sit on the standard scale and the calories your body burns at rest as a planning baseline.
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.