ProblemSolverTools — 147 free problem-solving tools that just work.
ProblemSolverTools at problemsolvertools.online brings you 147 free tools for the problems people actually search for — mortgage and BMI calculators, PDF merging, image compression, JSON formatting and more. Each one runs entirely in your browser.
Finance & Money
14 toolsMortgage Calculator
Monthly payment, total interest, payoff date and a full amortisation schedule — with tax, insurance and PMI kept separate, the way Calculator.net does it.
Finance & MoneyLoan / EMI Calculator
Monthly EMI for a personal, car or home loan, with total interest and an amortisation schedule.
Finance & MoneyAuto Loan Calculator
Compare dealer finance offers including trade-in value and sales tax.
Finance & MoneyCompound Interest Calculator
See savings or investments grow with regular monthly deposits, year by year.
Finance & MoneySimple Interest Calculator
Quick interest on a fixed deposit or an informal loan.
Finance & MoneyRetirement & Savings Goal Calculator
How much you must save each month to reach a target by a set date.
Finance & MoneyInvestment / ROI Calculator
Judge whether an investment was worth it: ROI %, net profit and annualised return (CAGR).
Finance & MoneySIP / Recurring Investment Calculator
Project monthly mutual-fund-style investing (SIP), popular in India.
Finance & MoneySalary Converter (Hourly ↔ Annual)
Convert a job offer between hourly pay and annual salary, with daily, weekly and monthly equivalents.
Finance & MoneySales Tax / VAT Calculator
Add tax to a net price, or strip it out of a tax-inclusive total — correctly.
Finance & MoneyTip Calculator & Bill Split
End the restaurant-table argument: tip, total and per-person split in one tap.
Finance & MoneyDiscount Calculator
Is the sale price actually good? Handles stacked discounts correctly — they multiply, they don't add.
Finance & MoneyCredit Card Payoff Calculator
See how long a balance really takes to clear — and what minimum payments cost you.
Finance & MoneyDebt-to-Income (DTI) Calculator
Check whether a lender is likely to approve you, using the ratio they actually look at.
Finance & MoneyHealth & Fitness
13 toolsBMI Calculator
Body Mass Index with the WHO/CDC adult category and the healthy weight range for your height.
Health & FitnessBMR Calculator
Basal Metabolic Rate — the calories your body burns at complete rest — via Mifflin-St Jeor.
Health & FitnessTDEE / Calorie Calculator
How many calories to eat to lose, maintain or gain weight, from your BMR and activity level.
Health & FitnessMacro Calculator
Split your daily calories into protein, carbs and fat grams for your goal.
Health & FitnessBody Fat % Calculator
US Navy circumference method — because BMI can't tell muscle from fat.
Health & FitnessIdeal Weight Calculator
A realistic target range from four published formulas — not one falsely precise number.
Health & FitnessPregnancy Due Date Calculator
Estimated due date from your last period or conception date, using Naegele's rule (ACOG).
Health & FitnessOvulation & Fertile Window Calculator
Your likely ovulation day and fertile window from your cycle dates.
Health & FitnessPeriod Calculator
Predict your next three periods and likely ovulation days for planning.
Health & FitnessRunning Pace Calculator
Enter any two of time, distance and pace — get the third, plus kilometre splits.
Health & FitnessHeart Rate Zone Calculator
Training zones 1–5 by % of max heart rate and by the Karvonen (heart-rate reserve) method.
Health & FitnessWater Intake Calculator
A daily hydration target from your weight and activity.
Health & FitnessSleep Calculator
Wake up between 90-minute sleep cycles instead of in the middle of one.
Health & FitnessMath & Education
14 toolsPercentage Calculator
The web's most-searched calculator (2.24M searches/month in SEMrush data for one competitor alone): % of a number, what %, and % change.
Math & EducationScientific Calculator
A real calculator when you don't have one: trig, logs, powers, roots and constants, with history.
Math & EducationFraction Calculator
Add, subtract, multiply and divide fractions and mixed numbers, fully simplified.
Math & EducationGPA Calculator
Semester and cumulative GPA on the standard 4.0 scale, weighted by credit hours.
Math & EducationFinal Grade Calculator
What do you need on the final exam to get the grade you want?
Math & EducationGrade / Test Score Calculator
Convert marks into a percentage and letter grade instantly.
Math & EducationMean, Median, Mode & Range
Paste a list of numbers for an instant statistics summary.
Math & EducationStandard Deviation Calculator
Spread of a dataset, with both sample and population standard deviation.
Math & EducationRatio & Proportion Calculator
Solve a/b = c/x, simplify ratios, and scale recipes, maps and mixtures.
Math & EducationQuadratic Equation Solver
Solve ax² + bx + c = 0 with real or complex roots, discriminant and vertex.
Math & EducationPythagorean Theorem Calculator
Find the missing side of a right triangle.
Math & EducationArea Calculator
Areas of common shapes, with the formula for each — a top school-search topic (1.22M searches/month in SEMrush data).
Math & EducationVolume Calculator
Volumes of cubes, boxes, cylinders, spheres, cones and pyramids.
Math & EducationSlope & Line Calculator
Slope, equation, midpoint and distance between two points.
Math & EducationText, Writing & SEO
13 toolsWord Counter
Words, characters, sentences, paragraphs and reading time — counted live as you type. One of the most-used tools on every tool hub.
Text, Writing & SEOCharacter Counter
Live character counts checked against X, title-tag, meta-description, LinkedIn and other real platform limits.
Text, Writing & SEOCase Converter
Fix ALL-CAPS accidents or convert headings: upper, lower, Title, Sentence, aLtErNaTiNg, camelCase, snake_case and more.
Text, Writing & SEORemove Duplicate Lines
Clean lists, email addresses and keyword sets — duplicates gone, count shown.
Text, Writing & SEOText Diff Checker
What changed between two drafts? Line-by-line differences, highlighted.
Text, Writing & SEOReadability Calculator
Is this text too hard for its audience? Flesch Reading Ease and Flesch-Kincaid grade level.
Text, Writing & SEOReading & Speaking Time Calculator
How long an article, script or speech actually runs.
Text, Writing & SEOKeyword Density Checker
An SEO sanity check — see your top 1, 2 and 3-word phrases and their density.
Text, Writing & SEOSlug Generator
Turn a post title into a clean URL slug.
Text, Writing & SEOFind & Replace
Bulk text edits without opening a word processor — with a replacement count.
Text, Writing & SEOSort Lines / Alphabetiser
Order any list alphabetically or numerically, ascending or descending, with optional de-duplication.
Text, Writing & SEOText Reverser & Line Shuffler
Reverse characters, words or lines — or shuffle lines into a random order.
Text, Writing & SEOMeta Tag & Title Length Checker
Preview exactly how your page will look in Google results, with pixel-width measurement.
Text, Writing & SEODeveloper & Coding
13 toolsJSON Formatter & Validator
Make unreadable API JSON readable, minify it, and pinpoint syntax errors with line and position.
Developer & CodingJSON ↔ CSV Converter
Move data between APIs and spreadsheets in both directions.
Developer & CodingBase64 Encoder / Decoder
Encode text for APIs and data-URIs, or decode Base64 back — UTF-8 safe.
Developer & CodingURL Encoder / Decoder
Fix broken links and query strings with proper percent-encoding.
Developer & CodingJWT Decoder
Inspect a token's header and claims, with a live expiry countdown. Decoding is not verification — the signature is not checked.
Developer & CodingRegex Tester
Build a pattern that actually matches: live highlighting, match list and capture groups.
Developer & CodingSQL Formatter
Make generated queries reviewable: indented, with keywords upper-cased.
Developer & CodingMarkdown Editor & Preview
Write README and docs with a live preview, and export the HTML.
Developer & CodingHTML Entity Encoder / Decoder
Stop &, < and > breaking your pages — encode or decode HTML entities.
Developer & CodingUnix Timestamp Converter
What date is 1735689600? Epoch ↔ human date in UTC and your local time, plus relative time.
Developer & CodingCron Expression Explainer
When does 0 3 * * 1 actually run? Plain-English translation plus the next 5 run times.
Developer & CodingIP Subnet Calculator
Plan networks and CIDR ranges: network, broadcast, usable hosts and ranges.
Developer & CodingLorem Ipsum Generator
Placeholder copy for mock-ups — paragraphs, sentences or words, classic or hipster-free plain Latin.
Developer & CodingUnit & Data Converters
13 toolsTemperature Converter
°C ↔ °F ↔ Kelvin for weather, cooking and science — with the formula shown.
Unit & Data ConvertersNumber Base Converter
Binary, octal, decimal and hex side by side — for CS classes and developers.
Unit & Data ConvertersCooking Measurement Converter
Cups ↔ grams by ingredient — because a cup of flour is not a cup of sugar.
Unit & Data ConvertersLength Converter
cm ↔ inches, km ↔ miles, feet ↔ metres — with a full table for the value you enter.
Unit & Data ConvertersWeight Converter
kg ↔ lb ↔ oz ↔ stone for health, luggage and recipes.
Unit & Data ConvertersArea Converter
m² ↔ ft² ↔ acres ↔ hectares for property listings and land.
Unit & Data ConvertersVolume Converter
Litres ↔ gallons ↔ cups ↔ ml for recipes and fuel. US units.
Unit & Data ConvertersSpeed Converter
km/h ↔ mph ↔ m/s ↔ knots.
Unit & Data ConvertersData Storage Converter
MB ↔ GB ↔ TB with the SI (1000-based) vs IEC (1024-based) distinction made explicit.
Unit & Data ConvertersTime Unit Converter
Seconds ↔ minutes ↔ hours ↔ days ↔ weeks ↔ years.
Unit & Data ConvertersPressure Converter
bar ↔ psi ↔ atm ↔ Pa for tyres, machines and weather.
Unit & Data ConvertersEnergy Converter
Joules ↔ calories ↔ kWh ↔ BTU.
Unit & Data ConvertersPower Converter
Watts ↔ horsepower ↔ kW for engines and appliances.
Unit & Data ConvertersDate & Time
11 toolsAge Calculator
Exact age in years, months and days for forms, school and eligibility — plus total days and your next birthday.
Date & TimeDate Difference Calculator
Days between two dates for deadlines, tenures and countdowns — with a years/months/days breakdown.
Date & TimeDate Add / Subtract Calculator
'90 days from today is…' — add or subtract days, weeks, months or years.
Date & TimeBusiness Days Calculator
Working days between dates, with a configurable weekend and your own holiday list — no country's holidays are assumed for you.
Date & TimeCountdown Timer
A live countdown to any event, exam or deadline.
Date & TimeStopwatch & Timer
Timing tasks, cooking and workouts — laps included, no app install.
Date & TimeTime Zone Converter
3pm in London is what in Karachi or New York? Converted with the browser's Intl time-zone database, daylight saving included.
Date & TimeWeek Number Calculator
ISO week number and day of year for planning and reporting.
Date & TimeWork Hours / Timesheet Calculator
Weekly hours and gross pay from clock-in and clock-out times.
Date & TimePomodoro Timer
Focus sessions with automatic work/break cycles and a session counter.
Date & TimeDay-of-Week Finder
The weekday of any historical or future date — plus its zodiac sign and day-of-year.
Date & TimeEveryday Life & Home
12 toolsBill Splitter
Split a shared meal or household bill fairly, with tax and tip handled per person.
Everyday Life & HomePaint Calculator
How many litres and cans to buy — doors, windows and coats accounted for.
Everyday Life & HomeTile / Flooring Calculator
Tiles and boxes to order, including the wastage professionals always add.
Everyday Life & HomeConcrete Calculator
Volume and bag count for a slab, footing or post hole.
Everyday Life & HomeElectricity Cost Calculator
What does this appliance actually cost to run — per day, month and year?
Everyday Life & HomeFuel Cost & MPG Calculator
Budget a trip's fuel, or work out your car's real efficiency.
Everyday Life & HomeRecipe Scaler
Scale a recipe up or down — paste ingredients with quantities, get the new amounts.
Everyday Life & HomeShoe Size Converter
Buy shoes from foreign stores: US, UK, EU and foot length side by side.
Everyday Life & HomeRoman Numeral Converter
Numbers ↔ Roman numerals for dates, chapters and clock faces (1–3999).
Everyday Life & HomeUnit Price Comparison
Which pack size is actually cheaper? Compare up to four products by price per unit.
Everyday Life & HomeMulch / Gravel Calculator
Garden material volume, bag count and approximate weight for a bed or path.
Everyday Life & HomeWallpaper Calculator
Rolls needed without over-buying — pattern repeat accounted for.
Everyday Life & HomeBusiness & Marketing
11 toolsProfit Margin & Markup Calculator
Price products without losing money: margin, markup and selling price in both directions.
Business & MarketingBreak-Even Calculator
How many sales before this product or business starts making profit?
Business & MarketingInvoice Generator
A professional, printable invoice without accounting software — generated entirely in your browser.
Business & MarketingFreelance Rate Calculator
Convert a salary goal into the hourly rate you actually need to charge.
Business & MarketingCPM / CPC / CPA Calculator
Make sense of ad-platform reports: enter any values, get the rest.
Business & MarketingConversion Rate Calculator
Your conversion rate, and what small improvements are worth in revenue.
Business & MarketingYouTube / AdSense Earnings Estimator
Rough creator income expectations from views and niche RPM — labelled as the estimate it is.
Business & MarketingEmail Signature Generator
A professional email signature in minutes — copy the HTML or the rendered signature.
Business & MarketingMulti-Rate Tax Quote Calculator
Quotes and invoices where different lines carry different tax rates — done correctly, per rate.
Business & MarketingMeeting Cost Calculator
What does this meeting really cost? The number that makes people rethink recurring invites.
Business & MarketingHashtag & Caption Planner
Check a caption against each platform's limits and count its hashtags before you post.
Business & MarketingSecurity & Generators
11 toolsPassword Generator
Strong, unique passwords from your device's cryptographic random generator. Nothing is sent anywhere or stored.
Security & GeneratorsPassword Strength Checker
Is your password actually safe? Entropy, crack-time estimates and concrete fixes. Your password never leaves this page.
Security & GeneratorsQR Code Generator
QR codes for links, Wi-Fi networks and contact cards, downloadable as PNG.
Security & GeneratorsUUID Generator
Generate random (v4) or time-ordered (v7) unique IDs for development and test data.
Security & GeneratorsRandom Number Generator
Unbiased random numbers for draws, games and sampling — cryptographic RNG, not Math.random().
Security & GeneratorsRandom Picker / List Shuffler
Pick a fair winner from a list, or shuffle a list into a provably random order (Fisher–Yates with crypto RNG).
Security & GeneratorsRandom Team Generator
Split a class, squad or workshop into balanced random teams.
Security & GeneratorsDice Roller & Coin Flip
Roll any dice combination, flip coins, and see the totals — for games and probability demos.
Security & GeneratorsPIN & Passphrase Generator
Memorable-but-strong passphrases from random words, or PINs of any length.
Security & GeneratorsHash Generator (SHA-1 / SHA-256 / SHA-512)
Checksums for text using the Web Crypto API built into your browser.
Security & GeneratorsFake / Test Data Generator
Dummy names, emails and addresses for testing forms and databases. Clearly fake — never use for real accounts.
Security & GeneratorsImage & Colour
12 toolsImage Compressor
Shrink photos for upload limits and email — processed on your device, never uploaded.
Image & ColourImage Resizer
Exact pixel sizes for avatars, application forms and marketplaces.
Image & ColourImage Cropper
Centre-crop to 1:1, 16:9, 4:5, passport-style ratios and more.
Image & ColourImage Format Converter
JPG ↔ PNG ↔ WebP without installing software.
Image & ColourColour Picker & HEX ↔ RGB ↔ HSL Converter
One colour, every format a developer or designer needs — with copy buttons.
Image & ColourColour Palette Generator
A harmonious 5-colour palette from any base colour: complementary, analogous, triadic and more.
Image & ColourCSS Gradient Generator
Design a gradient visually, then copy production-ready CSS.
Image & ColourWCAG Contrast Checker
Is that text actually readable? Contrast ratio with AA/AAA pass-fail for normal and large text.
Image & ColourFavicon Generator
A full favicon set from one image or emoji: 16, 32, 180, 192 and 512 px.
Image & ColourImage to Base64
Embed small images directly in CSS or HTML as a data-URI.
Image & ColourEXIF Viewer & Remover
See the camera and GPS data hidden in a photo — and strip it before sharing. Read locally; nothing is uploaded.
Image & ColourSVG to PNG Converter
Rasterise vector logos and icons at any size.
Image & ColourPDF & Files
10 toolsMerge PDF
Combine forms, certificates and scans into one PDF — entirely in your browser. Your files never leave your device, unlike server-side tools that upload them.
PDF & FilesSplit PDF / Extract Pages
Send only the relevant pages: extract a page range into a new PDF.
PDF & FilesRotate PDF Pages
Fix scanned upside-down or sideways pages and save a corrected PDF.
PDF & FilesImages to PDF
Turn phone photos of documents into one clean PDF.
PDF & FilesPDF to Images
Render PDF pages as PNG images for slides, posts and previews.
PDF & FilesText to PDF
A clean, printable PDF document from plain text.
PDF & FilesPDF Page Counter & Info
How many pages, what size, what metadata? Read locally — the file is never uploaded.
PDF & FilesCSV Viewer & Cleaner
Preview, de-duplicate, sort and re-export a CSV without opening Excel.
PDF & FilesFile Hash Checker
Verify a download wasn't corrupted or tampered with: its SHA-256 checksum, computed locally.
PDF & FilesWord Count for Files
Count words and characters in a .txt or .md document.
PDF & Files