Calculators — Guides & Articles

• How to Calculate Target Heart Rate for Fat Burning

  Published 2026-09-13

  Use the Karvonen formula to find your fat-burning heart rate. Enter age, resting pulse and intensity for a personalized training bpm.

  

• How to Calculate Sunrise and Sunset Using an Almanac

  Published 2026-09-13

  Calculate sunrise and sunset using almanac formulas. Enter date, latitude, longitude, and UTC offset to get NOAA-style apparent times from 1901 to 2099.

  

• How to Calculate Cylinder Volume in Cubic Meters

  Published 2026-09-12

  Cylinder volume in cubic meters uses V = πr²h with each length converted to meters first. See the exact conversion and how a calculator handles m³ output.

  

• How to Calculate Sphere Surface Area and Volume

  Published 2026-09-12

  Calculate sphere surface area with A = 4πr² and volume with V = (4/3)πr³. Step-by-step method, unit handling, scaling rules, and a free browser tool.

  

• How to Calculate Speed of Sound Wave: Formula and Method

  Published 2026-09-12

  Calculate the speed of a sound wave from air temperature using the ideal-gas formula a = √(γRT). Step-by-step calculator walkthrough, constants explained.

  

• km/h to m/s: The Exact Conversion Factor Explained

  Published 2026-09-12

  Convert speed from km/h to m/s using the exact factor 3.6, derived from 1,000 m per kilometer and 3,600 s per hour. Formula, example, and converter included.

  

• How to Calculate Sector Area in Radians: A = ½θr²

  Published 2026-09-11

  Use A = ½θr² to calculate sector area in radians. Follow the steps, see a worked example, and try the Sector Area Calculator for radius in any unit.

  

• Convert Seconds to HH:MM:SS Format Without Wrapping at 24

  Published 2026-09-11

  Convert any whole number of seconds into HH:MM:SS duration format. Hours stay above 23 for multi-day times. Exact integer arithmetic, free browser tool.

  

• How to Calculate Scientific Notation on TI-84

  Published 2026-09-11

  Calculate scientific notation on a TI-84 using the EE key and MODE menu. Switch to a free online Scientific Calculator for instant trig, logs, and powers.

  

• Calculate Rounding in Excel: Functions, Modes and Cases

  Published 2026-09-11

  Round numbers in Excel with ROUND, ROUNDUP, ROUNDDOWN, MROUND and INT. See why 1.005 rounds to 1.00, then verify with five exact rounding modes.