Calculators— Guides & Articles

• How to Change Time Zone for Any City

  Published 2026-08-15

  Convert any time between world zones with a DST-aware tool. See the exact local time, date, weekday, and UTC offset for any city around the world.

  

• How to Calculate Duration in Days Between Two Dates

  Published 2026-08-15

  Calculate duration in days between any two date-times. Get the breakdown plus total days, hours, minutes, and seconds with the Time Duration Calculator.

  

• Convert Time to Decimal: Hours, Minutes, and Seconds

  Published 2026-08-15

  Convert time to decimal in hours, minutes, or seconds with the free Time Converter. Ten units at once, live results, and full privacy — runs in your browser.

  

• How to Calculate Tile Backsplash Square Footage

  Published 2026-08-14

  Calculate tile backsplash square footage from length, height, and tile size. Convert mixed units and get whole-tile and box counts to order.

  

• How to Convert Temperature from Celsius to Fahrenheit

  Published 2026-08-14

  To convert Celsius to Fahrenheit, multiply by 9/5 and add 32. Use the Temperature Converter for instant, NIST-traceable results among °C, °F, K, and °R.

  

• How to Calculate Target Heart Rate for Exercise Zones

  Published 2026-08-14

  Use the Karvonen formula to find your target heart rate for exercise. Enter age, resting HR, and intensity to see your training bpm zone instantly.

  

• How to Calculate Sunrise and Sunset on a Ship

  Published 2026-08-14

  Calculate sunrise, sunset, and solar noon for a vessel's position with a NOAA-style estimator that asks for date, coordinates, and civil UTC offset.

  

• How to Calculate Ball Volume Using the Sphere Formula

  Published 2026-08-14

  Find the volume of any ball using the sphere volume formula V = 4πr³/3. Enter radius or diameter in cm, inches, or other units for instant cubic results.

  

• How to Calculate Speed of Sound at Different Altitudes

  Published 2026-08-14

  Estimate the speed of sound at different altitudes with the ideal-gas formula. Convert a dry-air temperature to m/s, km/h, mph, and knots in one step.

  

• Read Speed vs Write Speed: Convert Speeds Accurately

  Published 2026-08-14

  Comparing speeds you read in one unit against speeds you wrote in another? Use Speed Converter with exact m/s, km/h, mph, knots, and ft/s relationships.