Electricity Calculator

  • Electricity Usage From Meter Reading Calculator
    Calculate kWh used between two electricity meter readings. Enter current and previous readings plus a meter multiplier to get usage and estimated cost.
  • EV kWh per 100 km Calculator
    Calculate your electric vehicle energy consumption in kWh per 100 km from the energy used and distance driven. Get km/kWh and Wh/km too.
  • Milliamps to Amps Calculator
    Convert milliamps (mA) to amps (A) instantly. Enter a current in mA and get the value in amperes using A = mA / 1000.
  • kWh to BTU Calculator
    Convert kilowatt-hours (kWh) to British Thermal Units (BTU) instantly. Enter kWh and get BTU using the factor 1 kWh = 3412.142 BTU.
  • Amps to Milliamps Calculator
    Convert amps (A) to milliamps (mA) instantly. Enter a current value in amperes and get the equivalent in milliamps using mA = A × 1000.
  • Battery Amp-Hours Needed Calculator
    Calculate the battery amp-hours (Ah) needed from watts, runtime hours and voltage. Includes depth-of-discharge adjustment for any 12V, 24V or 48V battery.
  • Battery State of Charge Calculator
    Estimate battery State of Charge (SOC %) from a measured voltage reading using linear interpolation between empty (Vmin) and full (Vmax) voltages.
  • Kilowatts to Watts Calculator
    Convert kilowatts (kW) to watts (W) instantly. Enter a power value in kW and get the exact result in watts using W = kW × 1000.
  • Watts to Kilowatts Calculator
    Convert watts (W) to kilowatts (kW) instantly. Just divide power in watts by 1000 to get kilowatts. Fast, accurate, free W to kW converter.
  • Solar Panel Battery Charge Time Calculator
    Estimate how many hours of sunlight a solar panel needs to charge a battery from your battery Wh, panel watts, and system efficiency.
  • Lumens Needed Calculator
    Calculate how many lumens you need to light a room. Multiply floor area (m²) by the recommended lux level to get total lumens for any space.
  • Thevenin Equivalent Calculator
    Compute the Thevenin equivalent of a circuit. Enter open-circuit voltage and short-circuit current to find Thevenin voltage Vth and resistance Rth.
  • Peak-to-Peak Voltage Calculator
    Convert between peak-to-peak (Vpp), peak (Vpeak) and RMS (Vrms) voltage for a sine wave. Enter any one value to get the others instantly.
  • Resistance Temperature Coefficient Calculator
    Calculate how a conductor resistance changes with temperature using R = R₀(1 + α·ΔT). Enter reference resistance, temperature coefficient and temperatures.
  • Battery C-Rate Calculator
    Calculate charge/discharge current from battery capacity and C-rate using I = C-rate × Capacity. Get amps plus the theoretical full charge/discharge time.
  • Synchronous Speed Calculator
    Calculate the synchronous speed of an AC motor or generator from supply frequency and number of poles using Ns = 120f/P. Get results in RPM and rev/s.
  • Volts to Watts Calculator
    Convert volts to watts instantly. Enter voltage (V) and current (A) to calculate electrical power in watts using P = V × I.
  • mAh to Wh Battery Capacity Calculator
    Convert battery capacity from mAh to Wh instantly. Enter milliamp-hours and voltage to get watt-hours and kilowatt-hours for any battery.
  • IoT Sensor Battery Life Calculator
    Estimate how long an IoT sensor or wireless device will run from its battery using capacity (mAh), average current draw (mA), and a usable-capacity derating factor.
  • Solar Panel Payback & ROI Calculator
    Calculate your solar panel payback period and ROI. Enter system cost, annual savings, and lifespan to see break-even years, lifetime savings, and return.
  • Solar Panel Number Calculator
    Calculate how many solar panels you need based on daily kWh energy use, panel wattage, peak sun hours, and system efficiency derating.
  • kVA Calculator
    Calculate apparent power in kVA from voltage and current for single-phase and three-phase circuits. Free, instant kVA calculator with formula.
  • Generator Size Calculator
    Calculate the right generator size in watts. Add running watts plus the largest starting surge, with a safety margin, to size your generator correctly.
  • Device Power Consumption Cost Calculator
    Calculate how much electricity a device costs to run. Enter watts, hours per day, days and your price per kWh to get total and daily running cost.

Categories