Popular Tools

Quickly estimate fetal weight using ultrasound data like Biparietal Diameter (BPD), Abdominal Circumference (AC), and Femur Length (FL). Uses the Hadlock formula to provide a reliable reference for pregnancy assessment.

Generate correctly formatted random email addresses in bulk, with customizable domains and prefix rules — ideal for testing sign-ups and protecting privacy.

A pixel (PX) to point (PT) unit conversion tool for designers and developers. Supports custom PPI for typography and layout adaptation.

Calculate the minimum daily calories your body needs at rest based on gender, height, weight, and age. Get a scientific reference for your diet and fitness plans.

Convert between Simplified Chinese, Traditional Chinese, and Martian text (Huoxingwen) for stylized messages, profiles, and nicknames.

Calculate your body fat percentage using BMI and waist circumference formulas. Get instant body composition insights for fitness and health management.

Provides controllable random color generation for designers and developers, supporting multiple formats and hue filtering.

Calculate six trigonometric functions from radian values with custom decimal precision.

Generate random browser User-Agent strings for developers, QA testers, and web scrapers to simulate various devices and platforms.

Accurately calculate traditional memorial dates including the First Seven, Third Seven, Fifth Seven, and Seventh Seven. Supports both Lunar and Gregorian calendar inputs to help families follow traditional mourning customs.

Calculate the Future Value Interest Factor of an Annuity (FVIFA) instantly. Enter your interest rate and periods to estimate the future value of regular investments with this free online calculator.

Quickly generate random, fake Chinese addresses complete with provinces, cities, districts, streets, and postal codes. Perfect for software testing and mock data generation.

Quickly calculate VAT-inclusive prices, VAT-exclusive prices, and tax amounts with this free online VAT calculator. Supports custom tax rates.

Free online Caesar cipher encryption and decryption tool. Supports custom alphabets and shift offsets. Ideal for cryptography learning and fun.

Calculate your Body Mass Index (BMI) and assess your health status based on height and weight. Ideal for personal health monitoring.

A two-way IPv4 and IPv6 address converter for network configuration, debugging, and format validation.

Accurately calculate your cup and bra size using your bust and underbust measurements to find the perfect fitting bra.

Instantly identify prime, composite, or special numbers. Supports batch checking and mathematical property analysis.

Generate random integers or decimals within a specified range, featuring duplicate removal, sorting, and formatted output.

Calculate Body Surface Area (BSA) based on height and weight using multiple medical formulas. Ideal for medication dosage estimation and physiological research.