How do I convert time between time zones online?

Enter your time in the input field, select your source time zone, and choose your destination zone — the converted time updates automatically. For scheduling meetings across multiple cities, use the World Clock & Scheduler which shows hourly time slots in up to 4 cities and lets you add the meeting to Google Calendar, Office 365, or Outlook directly.

How many kilometers are in a mile?

One mile equals exactly 1.609344 kilometers. To convert miles to kilometers, multiply the number of miles by 1.609344.

How do I convert Celsius to Fahrenheit?

To convert Celsius to Fahrenheit, multiply the temperature by 9/5 and add 32. For example, 100°C × 9/5 + 32 = 212°F.

How many pounds are in a kilogram?

One kilogram equals approximately 2.20462 pounds. To convert kilograms to pounds, multiply by 2.20462.

How many centimeters are in an inch?

One inch equals exactly 2.54 centimeters. This is a fixed conversion factor: to convert inches to cm, multiply by 2.54; to convert cm to inches, divide by 2.54.

How is BMI calculated?

BMI is calculated as weight in kilograms divided by height in metres squared (BMI = kg / m²). Categories: Underweight under 18.5, Normal 18.5–24.9, Overweight 25–29.9, Obese 30 and above.

What is compound interest and how do I calculate it?

Compound interest grows by earning interest on previously earned interest. The formula is A = P × (1 + r/n)^(n×t), where P is the principal, r is the annual rate, n is the compounding frequency, and t is the time in years. Use the Rule of 72 (72 ÷ rate%) to estimate doubling time.

Are exchange rates live and accurate?

Yes — currency rates come from the European Central Bank (ECB) via the Frankfurter API, updated daily. The historical chart shows 7, 30, or 90 days of rate movement for any supported currency pair.

Roman Numeral Converter — Numbers to Roman & Back

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X10

L50

C100

D500

M1000

IV4

IX9

XL40

XC90

CD400

CM900

💡 Pro tip: roman.proTip

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Convert All !

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