Free calculators for developers, travelers, beer lovers & parents
Developer
JSON Formatter & Validator
Instantly format, pretty-print, or minify JSON. Catches syntax errors and highlights the exact line — no login, no uploads, all in your browser.
Password Generator
Generate strong, secure passwords instantly. Customize length and character types — uppercase, lowercase, numbers, symbols. All generated in your browser using cryptographically secure randomness. Nothing is sent to any server.
Travel
Visa Requirement Checker
Check visa requirements for your passport and destination country instantly. Find out whether you need a visa, an e-Visa/ETA, or can enter visa-free — plus general travel insurance guidance. Based on a static reference snapshot; always verify with the official consulate before travel.
Flight Delay Compensation Calculator
Find out if your delayed flight qualifies for compensation under EU Regulation 261/2004 or US DOT rules. Select your regulation, route distance, delay duration, and cause to get an instant estimate — no sign-up required.
Beer
BAC Calculator (Blood Alcohol Concentration)
Estimate your Blood Alcohol Concentration (BAC) using the Widmark formula. Enter your sex, weight, drinks consumed, and time elapsed to get an instant estimate — for informational reference only. Never use this to judge fitness to drive.
Homebrew Recipe & ABV Calculator
Calculate estimated ABV from Original Gravity (OG) and Final Gravity (FG) using the standard homebrewing formula. Includes a dilution calculator to hit your target alcohol percentage. All calculations run in your browser — no login, no uploads.
Baby
Baby Growth Percentile Calculator
Calculate your baby's weight and height/length percentiles (0–60 months) using WHO or CDC growth standards. Enter sex, age, weight, and height to instantly see where your child falls on the growth chart. For informational reference only — always consult a paediatrician for clinical assessment.
Baby Sleep Schedule Calculator
Enter your baby's age and today's wake-up time to get a recommended nap schedule and bedtime — based on age-appropriate wake windows and nap durations. For general reference only; always consult a paediatrician for individual sleep concerns.
Recently Added
Baby Growth Percentile Calculator
Calculate your baby's weight and height/length percentiles (0–60 months) using WHO or CDC growth standards. Enter sex, age, weight, and height to instantly see where your child falls on the growth chart. For informational reference only — always consult a paediatrician for clinical assessment.
Baby Sleep Schedule Calculator
Enter your baby's age and today's wake-up time to get a recommended nap schedule and bedtime — based on age-appropriate wake windows and nap durations. For general reference only; always consult a paediatrician for individual sleep concerns.
JSON Formatter & Validator
Instantly format, pretty-print, or minify JSON. Catches syntax errors and highlights the exact line — no login, no uploads, all in your browser.
Password Generator
Generate strong, secure passwords instantly. Customize length and character types — uppercase, lowercase, numbers, symbols. All generated in your browser using cryptographically secure randomness. Nothing is sent to any server.