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⚡ Featured Tools
Our most innovative tools — AI, peer-to-peer, and developer favorites.
AI Background Remover
Remove image backgrounds with AI, directly in your browser. No server, no upload — the neural network runs 100% locally.
AI Depth Map
Estimate depth from any image with AI, directly in your browser. Colorized depth visualization — no server, no upload, 100% local.
Local AI Text-to-Speech
Convert text to natural-sounding audio using AI. Runs entirely in your browser — your text never leaves your device.
Flowelio Drop — Private P2P File Transfer
Send files directly between devices without any server. Your files never pass through Flowelio. Works on WiFi and across networks. Free, no account needed.
Collab Editor
Real-time P2P collaborative code editor. All data stays in your browser.
Flowelio Paste
Private encrypted paste sharing. The decryption key never leaves your browser.
JSON Formatter/Validator
Format, minify, and validate JSON. Supports customizable indentation.
Regex Tester
Test and debug regular expressions with real-time matching, highlighting, and replacement. Supports all JavaScript regex flags.
Flowelio is the most comprehensive free online calculator platform. Calculate your net salary, taxes, BMI, compound interest, and much more — instantly, with no registration, from any device.
🔥 Most popular
The calculators our users love the most
BMI Calculator
Calculate your Body Mass Index (BMI) by entering your weight and height.
Compound Interest Calculator
Discover how your investment grows with compound interest.
Percentage Calculator
Calculate percentages in 5 different modes.
TDEE & BMR Calculator
Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE).
ROI Calculator
Calculate your Return on Investment (ROI) with annualized and inflation-adjusted analysis.
Unit Converter
Convert between different units of measurement: length, weight, volume, area, and speed.
Health
Monitor your physical well-being with professional calculators: calculate your BMI to know your ideal weight, basal metabolic rate (TDEE) for calorie management, body fat percentage, running pace, and race time predictions.
BMI Calculator
Calculate your Body Mass Index (BMI) by entering your weight and height.
TDEE & BMR Calculator
Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE).
1RM Calculator
Estimate your one-rep max from the weight lifted and number of reps.
Water Intake Calculator
Calculate how much water you should drink daily based on weight, age, activity, and climate.
Body Fat Calculator
Estimate your body fat percentage using the US Navy method.
Calories Burned Calculator
Estimate calories burned during physical activity.
Finance
Financial tools for informed decisions: calculate compound interest, ROI on investments, profit margins, break-even point, and analyze savings with solar panels or your carbon footprint.
Compound Interest Calculator
Discover how your investment grows with compound interest.
ROI Calculator
Calculate your Return on Investment (ROI) with annualized and inflation-adjusted analysis.
Margin & Markup Calculator
Convert between margin and markup and calculate the selling price.
Break-Even Calculator
Calculate the break-even point for your business.
Split the Bill
Calculate the per-person amount including tax and tip.
Carbon Footprint Calculator
Estimate your annual carbon footprint.
Utility
Useful tools for everyday life: generate secure passwords, calculate days between dates, convert units of measurement and time zones, and estimate reading time for any text.
Secure Password Generator
Generate random, secure passwords with customizable criteria.
Days Between Dates Calculator
Calculate the number of days between two dates.
Percentage Calculator
Calculate percentages in 5 different modes.
Reading Time Calculator
Analyze a text: reading time, speaking time, words, characters, sentences, and paragraphs.
Unit Converter
Convert between different units of measurement: length, weight, volume, area, and speed.
Timezone Converter
Convert time between different time zones around the world.
Europe
European validation tools: verify IBAN codes and EU VAT numbers in real time.
USA
US financial and tax calculators: take-home pay, sales tax, tip, mortgage, auto loan, 401(k), and capital gains.
US Take-Home Pay Calculator
Calculate your net pay in the US with federal, state taxes and FICA.
US Sales Tax Calculator
Calculate sales tax based on state and local rates.
Tip Calculator
Calculate tip and split the bill.
US Mortgage Calculator
Calculate monthly mortgage payment with taxes and insurance.
401(k) Calculator
Estimate your 401(k) retirement savings growth.
Auto Loan Calculator
Calculate monthly auto loan payment.
United Kingdom
UK calculators: PAYE, Stamp Duty, VAT, student loan repayment, and pension.
UK PAYE Calculator
Calculate your UK net salary with Income Tax and National Insurance.
Stamp Duty Calculator
Calculate UK Stamp Duty Land Tax.
UK VAT Calculator
Add or remove UK VAT from an amount.
Student Loan Repayment Calculator
Calculate UK student loan repayments.
UK Pension Calculator
Estimate your UK pension with contributions and State Pension.
AI Tools
AI tools that run 100% in your browser using local neural network models. No server, no upload, total privacy: your data never leaves your device.
AI Background Remover
Remove image backgrounds with AI, directly in your browser. No server, no upload — the neural network runs 100% locally.
AI Depth Map
Estimate depth from any image with AI, directly in your browser. Colorized depth visualization — no server, no upload, 100% local.
Local AI Text-to-Speech
Convert text to natural-sounding audio using AI. Runs entirely in your browser — your text never leaves your device.
Dev Tools
Developer tools: hash generator, Base64, URL encoder, UUID, JWT decoder, JSON formatter, QR code, color picker, XML/CSV tools, barcode, and more.
Hash Generator
Generate SHA-1, SHA-256, SHA-384, SHA-512 hashes for any text. Supports HEX and Base64 output.
Base64 Encoder/Decoder
Encode and decode text to Base64 with Unicode support and URL-safe variant.
URL Encoder/Decoder
Encode and decode URLs with encodeURIComponent, decodeURIComponent, encodeURI, and decodeURI.
UUID Generator
Generate cryptographically secure random UUID v4. Supports batch generation and custom formats.
JWT Decoder
Decode and analyze JWT (JSON Web Token) tokens. View header, payload, expiry date, and claims.
HTML Escape/Unescape
Escape and unescape HTML entities (&, <, >, ", ').
Frequently Asked Questions
- Is Flowelio really free?
- Yes, all calculators on Flowelio are completely free, with no usage limits, no subscriptions, and no registration required. We do not collect personal data.
- Are the Italian tax calculations up to date?
- Yes, all Italian tax calculators (IRPEF, INPS, IMU, NASpI, flat-rate regime, flat rental tax, TFR, pension) are updated to 2026 rates and parameters according to the Agenzia delle Entrate and INPS regulations.
- How is the net salary calculated?
- The net salary calculator applies the 2026 IRPEF tax brackets (23% up to €28,000, 35% up to €50,000, 43% above) with employee INPS contributions (9.19% for private sector) and the deductions provided by current Italian tax law.
- How does the BMI calculator work?
- The BMI (Body Mass Index) calculator divides weight in kg by the square of height in meters, classifying the result according to WHO categories: underweight (<18.5), normal weight (18.5–24.9), overweight (25–29.9), and obesity (≥30).
- Are the calculator results reliable?
- Flowelio calculators use official formulas and up-to-date data, but provide estimates for informational purposes. For important decisions about taxes, finance, or health, we always recommend consulting a qualified professional (accountant, financial advisor, doctor).
- Can I use Flowelio on smartphone and tablet?
- Yes, Flowelio is designed to work perfectly on any device: smartphone, tablet, and desktop. The interface automatically adapts to your screen size for an optimal user experience.
The most comprehensive online calculator platform
Flowelio offers a complete suite of over 30 free online calculators organized into four main categories: health and fitness, finance and investments, everyday utilities, and Italy-specific calculators. Each calculator is designed to provide accurate, instant results directly in your browser.
For Italian workers and professionals, Flowelio includes tax calculators updated to 2026 for net salary calculation, flat-rate regime simulation, NASpI allowance, IMU for every municipality, car tax by region, flat rental tax, notary fees for home purchase, TFR (severance pay), and net pension.
For health and fitness enthusiasts, we offer calculators for BMI, basal metabolic rate (TDEE), 1RM for weightlifting, water intake, body fat percentage, calories burned, running pace, and race time predictions. For the world of finance: compound interest, ROI, margin and markup, break-even, bill splitting, and solar panel savings.