Utilities

  • Days Until Date Calculator
    Count the exact number of days until any future date with our free Days Until Date Calculator. Countdown to birthdays, holidays, deadlines and events.
  • Daily Electricity Usage Calculator
    Calculate daily, monthly and yearly electricity usage in kWh and cost from any appliance's wattage, hours of use, and your cost per kWh.
  • Appliance Run Time Battery Calculator
    Estimate how long a battery will power an appliance from its Ah capacity, voltage, load watts and system efficiency. Free runtime calculator.
  • Energy Cost Per Hour Calculator
    Calculate the electricity cost per hour of any appliance from its wattage and your kWh rate. See hourly, daily, monthly and yearly running costs instantly.
  • GPM to LPM Flow Rate Converter
    Convert flow rate from gallons per minute (GPM) to liters per minute (LPM) instantly. Also shows liters per hour and cubic meters per hour.
  • Watt-hour Calculator
    Calculate energy in watt-hours (Wh) and kilowatt-hours (kWh) from power in watts and run time in hours. Free, instant Wh = P × t calculator.
  • Tap Water Cost Calculator
    Calculate the cost of tap water from the volume used and your price per liter. Estimate water bills, showers, baths, gardens and more instantly.
  • Gas vs Electric Dryer Cost Calculator
    Compare the annual running cost of a gas vs electric clothes dryer (US). Enter loads, energy use and utility rates to see which is cheaper and your savings.
  • Electricity Cost – Single Usage Calculator
    Calculate the electricity cost of running a single appliance: enter its power in watts, hours used, and your price per kWh to get the exact cost.
  • Cost Per kWh Calculator
    Find your effective electricity rate per kWh by dividing your total monthly bill by the kilowatt-hours used. Fast, free energy cost calculator.
  • Number Base Converter
    Convert numbers between binary, octal, decimal, and hexadecimal instantly. Free online base converter with step-by-step decimal value shown.
  • Roman Numeral Converter
    Convert numbers to Roman numerals and Roman numerals back to numbers (1–3999). Free, instant converter using the standard subtractive notation.
  • Days Between Dates Calculator
    Find the exact number of days between two dates. Enter a start and end date to get the total days, signed difference, and weeks between them.
  • Kg to Lbs Calculator
    Convert kilograms to pounds instantly. Enter a weight in kg and get the exact pounds (and ounces) using the factor 1 kg = 2.2046226218 lbs.
  • Cm to Inches Calculator
    Convert centimeters to inches instantly. Enter a length in cm and get the exact inches using the 1 inch = 2.54 cm standard conversion.
  • Feet & Inches to Centimeters Calculator
    Convert height in feet and inches to centimeters instantly. Enter feet and inches to get the exact cm and meters using the 2.54 conversion factor.
  • Hex to RGB Color Converter
    Convert any hex color code (#RRGGBB or #RGB) to its RGB values instantly. See the red, green and blue channels plus a live color swatch.
  • Hourly to Yearly Pay Calculator
    Convert your hourly wage to yearly, monthly, and weekly pay instantly. Enter your hourly rate and weekly hours to estimate your annual salary.
  • Annual Appliance Running Cost Calculator
    Calculate the yearly electricity cost of any appliance from its wattage, daily usage hours, and your price per kWh. Get annual, monthly, and daily costs.
  • Shoe Size Converter
    Convert your foot length in cm to EU, US, and UK shoe sizes for men and women using Brannock-based linear sizing relations.
  • Gas Mileage (MPG) Calculator
    Calculate your car's gas mileage in miles per gallon (MPG) from miles driven and gallons used. Also shows L/100km and km/L equivalents.
  • Metric (SI Prefix) Units Conversion Calculator
    Convert a value between SI metric prefixes (giga, mega, kilo, milli, micro, nano and more) for any base unit. Instant powers-of-ten conversion factor.
  • Kilowatts to Amps Calculator
    Convert kilowatts (kW) to amps for DC, single-phase and three-phase AC circuits. Enter power, voltage and power factor to get current in amperes.
  • Water Heating Energy Calculator
    Calculate the energy needed to heat water using Q = m·c·ΔT. Enter volume, start/end temperature and efficiency to get kWh, kJ and joules.

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