Best Free BMI Calculator Online - Body Mass Index Calculator

Our BMI calculator is the most accurate free online body mass index calculator that instantly calculates BMI and provides health status classification. Perfect for fitness enthusiasts tracking weight loss progress, healthcare professionals screening patients, personal trainers monitoring clients, and individuals managing health goals. Real-time BMI calculation with weight in kg or pounds, height in cm or feet/inches, and detailed health status interpretation. Works for adults, teenagers, and children with age-specific BMI percentiles. Includes BMI chart, healthy weight range, and personalized recommendations.

Age Calculator - Calculate Exact Age from Date of Birth

Calculate your exact age with our precise age calculator. Determines age in years, months, weeks, days, hours, minutes, and seconds from birth date. Essential for filling forms requiring exact age, celebrating milestone birthdays, calculating retirement eligibility, determining school admission age, verifying age for legal requirements, and finding age differences between people. Accounts for leap years, varying month lengths, and time zones. Shows next birthday countdown, zodiac sign, birth day of week, and age in different time units. Perfect for age verification, birthday planning, and demographic surveys.

Date Calculator - Days Between Dates and Date Duration Calculator

Our comprehensive date calculator helps calculate days between two dates, add or subtract days from dates, find business days excluding weekends and holidays, calculate weeks and months between dates, and determine date differences for project planning. Essential for project managers tracking deadlines, pregnant women calculating due dates, travelers planning trip durations, students tracking semester lengths, HR professionals calculating employment tenure, and event planners organizing schedules. Supports multiple date formats, international calendars, and custom weekend definitions.

Percentage Calculator - Calculate Percentages, Increases, and Decreases

Calculate percentages instantly with our free percentage calculator. Find what percentage one number is of another, calculate percentage increase or decrease, add or subtract percentages from numbers, find original value before percentage change, and calculate percentage points difference. Ideal for students solving math problems, shoppers calculating discounts and sales tax, business analysts computing growth rates, investors tracking portfolio returns, teachers grading exams, and finance professionals analyzing financial statements. Shows step-by-step calculations and explanations.

Unit Converter - Convert Metric to Imperial and More

Convert between units instantly with our comprehensive unit converter. Supports length conversion (meters, feet, inches, kilometers, miles, yards, centimeters), weight conversion (kilograms, pounds, ounces, grams, tons), volume conversion (liters, gallons, milliliters, cups, pints, quarts), temperature conversion (Celsius, Fahrenheit, Kelvin), area conversion (square meters, acres, hectares, square feet), speed conversion (km/h, mph, m/s, knots), and more. Essential for international travelers, engineers, scientists, cooks following recipes, construction workers, and students. Accurate conversions with multiple decimal places.

Temperature Converter - Celsius, Fahrenheit, and Kelvin Conversion

Convert temperatures between Celsius, Fahrenheit, and Kelvin instantly. Our temperature converter uses precise formulas for accurate conversions: Celsius to Fahrenheit (°F = °C × 9/5 + 32), Fahrenheit to Celsius (°C = (°F - 32) × 5/9), Celsius to Kelvin (K = °C + 273.15), and all reverse conversions. Perfect for travelers adjusting to different temperature scales, students solving physics problems, cooks following international recipes, weather enthusiasts, scientists conducting experiments, and HVAC professionals. Includes temperature reference points like freezing and boiling points of water.

Timezone Converter - World Clock and Time Zone Calculator

Convert time between different time zones with our timezone converter. Find current time in any city worldwide, schedule meetings across time zones, convert specific times between zones, account for daylight saving time changes, and compare multiple time zones simultaneously. Essential for remote teams coordinating across continents, international business professionals scheduling calls, travelers planning itineraries, event organizers hosting global webinars, and anyone communicating with people in different time zones. Covers all major cities and time zones worldwide with automatic DST adjustments.

Loan Calculator - Mortgage and Loan Payment Calculator

Calculate loan payments and amortization schedules with our comprehensive loan calculator. Input loan amount (principal), annual interest rate, and loan term to calculate: monthly payment amount, total interest paid over loan lifetime, total amount repaid, amortization schedule showing principal vs interest breakdown, and payoff timeline. Supports mortgages, auto loans, personal loans, student loans, and business loans. Helps compare different loan offers, understand refinancing benefits, plan debt payoff strategies, and budget for major purchases. Includes extra payment calculator to see how additional payments reduce interest.

Why Choose Rune Calculator Tools?

Rune provides the best free calculator tools online with instant results, professional-grade accuracy, no registration required, complete privacy protection, mobile-friendly responsive design, and comprehensive explanations. Whether you need a BMI calculator for health tracking, age calculator for forms, date calculator for planning, percentage calculator for math, unit converter for measurements, temperature converter for recipes, timezone converter for meetings, or loan calculator for financial planning - Rune offers the complete calculator suite for students, professionals, and everyday users.

Calculator Tools Use Cases

• Health & Fitness: Calculate BMI for weight management; Track health metrics; Monitor fitness progress
• Students: Solve math problems; Calculate percentages; Convert units for science; Find age for forms
• Finance Professionals: Calculate loan payments; Analyze interest rates; Compute percentage changes; Plan budgets
• Project Managers: Calculate project durations; Find business days; Track deadlines; Plan timelines
• Travelers: Convert currencies; Calculate time zones; Convert temperature scales; Convert measurements
• Home Buyers: Calculate mortgage payments; Compare loan options; Understand amortization; Plan budgets
• Cooks & Chefs: Convert recipe measurements; Convert temperatures; Scale ingredient quantities
• Remote Workers: Convert time zones for meetings; Schedule across continents; Coordinate global teams
• Healthcare Professionals: Calculate BMI for patients; Determine medication dosages; Convert medical units
• Engineers & Scientists: Convert technical units; Calculate precise measurements; Perform accurate conversions

Supported Calculations and Conversions

All calculator tools support various calculation types and unit systems: BMI calculation for adults and children with WHO and CDC standards, age calculation in multiple time units with leap year accuracy, date calculations for business days and calendar days, percentage calculations for all common scenarios, unit conversions between metric and imperial systems, temperature conversions with scientific precision, timezone conversions for 400+ cities worldwide, and loan calculations with amortization schedules. Accurate formulas ensure reliable results for personal, professional, and educational use.