Free tools network

Free online calculators & tools

A directory of free calculators and utilities from our network — finance, construction, developer, text, time, health and more. All free, no sign-up, most run entirely in your browser.

Finance & Money

totalinterestcalc.comThe full lifetime cost of a mortgage or loan — total interest, amortization schedule and the effect of extra payments.indiaemi.comAn EMI calculator built for India — home, car and personal loans plus credit-card EMI with GST, advance vs arrears.marginvsmarkup.comConvert between margin and markup and price products correctly, clearing up the confusion that erodes profit.bestpercentagecalculator.netEvery everyday percentage problem — percentage of a number, change, increase, decrease and reverse — in one tool.

Solar, Electrical & Construction

voltdropcalc.comVoltage drop and correct wire gauge across NEC, CEC, BS 7671, AS/NZS and IEC standards.prosolarcalc.comProfessional solar sizing and design tools for installers and serious DIY builders.solarbatterybankcalc.comOff-grid and backup solar sizing with real engineering — usable capacity, C-rate, voltage and chemistry.backuppowercalc.comSize a generator or backup power system accurately, accounting for running loads and motor surge.actonnagecalc.comWork out air-conditioner tonnage and cooling load from area, climate, insulation and sun exposure.cubicyardage.comConcrete and bulk-material calculators in cubic yards for slabs, footings, columns, walls and stairs.concretematerialcalc.comCode-aligned concrete and construction calculators, from a single mix to a full costed BOQ.thesquarefootagecalculator.comSquare footage for floors, walls, rooms and land across many shapes, with unit conversion handled.staircalculators.netStaircase rise, run, stringer length and headroom to code, for straight and turning stairs.boxvolumecalculator.comVolume and capacity of boxes, cartons and rectangular containers in any units.tankvolumecalc.comVolume and fill level of tanks in many shapes — cylindrical, oval, rectangular and capsule.dimweightcalc.comDimensional (volumetric) weight for FedEx, UPS, USPS and others, compared against actual weight.girthcalculator.comPackage girth and combined length-plus-girth, checked against carrier oversize limits.roofingmaterialcalc.comEstimate shingles, underlayment and materials from your roof's area and pitch, with waste factored in.constructioncalchq.comA hub of construction calculators for materials, areas, volumes and project estimates in one place.poolvolumecalc.comFind pool water volume in gallons or litres for any shape and depth, for dosing chemicals and heating.

Developer & Web Utilities

jsontools.toolsFormat, validate, minify and explore JSON in your browser, with a tree viewer for messy payloads.base64decode.toolsEncode text and files to Base64 or decode them back, entirely client-side.urlencodedecode.comPercent-encode and decode URLs and query strings with full Unicode support.hashgenerator.toolsGenerate MD5, SHA-1, SHA-256 and other hashes from text or files for checksums and integrity checks.uuidcore.comGenerate UUIDs in bulk and learn how the versions differ, with copy-ready output.regexguide.comBuild, test and understand regular expressions with live matching and a plain-language reference.crontabsheet.comBuild cron schedules visually and read back exactly when a crontab expression runs.epochtime.toolsConvert between Unix epoch timestamps and human-readable dates in any time zone.cidrcalculator.netNetwork and broadcast addresses, host ranges and subnet sizes from CIDR notation.subnetmaskcalc.netSubnet masks, host counts and address ranges, with worked examples and code snippets.barcodeandqr.comGenerate barcodes and QR codes in many formats, export print-ready as PNG or PDF, all local.removemetadata.toolsStrip hidden metadata from images, PDFs, Office files, audio and video — entirely in your browser.corepdftools.comMerge, split, compress, rotate and password-protect PDFs client-side; files never leave your device.colorcodekit.comConvert color codes between HEX, RGB, HSL and more, build palettes and export design tokens.pictoolkit.comBrowser-based image utilities for resizing, converting and editing pictures without uploading.checkinternetspeed.toolsTest your download, upload and ping speed straight in the browser, with a clear latency read.checkmyipnow.comSee your public IP address along with location, ISP and browser details any website can detect.whoislookuppro.comLook up domain registration, ownership, expiry dates and DNS records for any website.

Text & Time

wordcounterfree.comCount words, characters, sentences and paragraphs and estimate reading time as you type.transformcase.comConvert text between upper, lower, title and sentence case in one click.textrepeat.netRepeat, duplicate and generate blocks of text quickly, with control over separators and counts.numtotext.comConvert numbers into words in the Indian rupee, lakh and crore format — for cheques and invoices.unitcheatsheet.comA fast reference and converter for length, weight, volume, temperature and more.calculatehours.netAdd up the hours between start and end times, including overnight spans and breaks.clockwithus.comCheck the current time across world cities and time zones at a glance.theagecalculator.netExact age in years, months and days, plus milestones and birthday countdowns.passwordstrength.netTest how strong a password is and how long it would take to crack, checked locally.

Health & Education

calorieskit.comCalorie, macronutrient and body-composition calculators with clear methodology behind every number.bmibmrcalc.comBMI, BMR and TDEE with activity levels and macro targets, plus goal planning and progress tracking.measurechef.comConvert cooking measurements between cups, grams, millilitres and more, ingredient-aware.fractionsteps.comStep-by-step fraction calculators that show the working, for students and teachers.gpacalculatorhq.comCalculate GPA and cumulative CGPA from letter grades and credit hours across common scales.