Physics and Engineering

  • Pump Power (HP) Calculator
    Calculate pump brake horsepower (BHP) and water horsepower from flow rate (GPM), total head (ft), specific gravity, and pump efficiency.
  • Mixing Two Fluids Final Temperature Calculator
    Calculate the final equilibrium temperature when two fluids are mixed, using mass, specific heat, and starting temperatures. Free physics tool.
  • Percent Efficiency Calculator
    Calculate percent efficiency from useful output and total input energy. Free online efficiency calculator using output/input × 100, with energy loss.
  • Valve Kv Flow Coefficient Calculator
    Calculate the valve flow coefficient Kv (metric) from flow rate, specific gravity and pressure drop. Get equivalent Cv too. Free engineering tool.
  • SCFM to ACFM Calculator
    Convert SCFM to ACFM using actual pressure and temperature. Free airflow conversion calculator for compressors, blowers, and HVAC systems.
  • Head Loss per 100 ft Calculator (Hazen-Williams)
    Calculate Hazen-Williams friction head loss in feet of water per 100 ft of pipe from flow rate (gpm), inside diameter, and C coefficient. US units.
  • Pump Hydraulic Power (kW) Calculator
    Calculate pump hydraulic power in kW from fluid density, gravity, flow rate and head using P = ρgQH. Also outputs watts, horsepower and shaft power.
  • Pump Brake Power & Efficiency Calculator
    Calculate pump brake (shaft) power from fluid density, flow rate, head and efficiency using P = ρgQH/η. Get kW and hp output instantly.
  • Pressure Drop from Flow Rate Calculator
    Calculate pipe pressure drop with the Darcy-Weisbach equation from friction factor, length, diameter, fluid density, and velocity. Get results in Pa, kPa, and bar.
  • Watt's Law Calculator
    Free Watt's Law calculator. Solve for power (P), voltage (V), or current (I) using P = V × I. Enter any two values to find the third instantly.
  • Electricity Units to kWh Calculator
    Convert electricity units to kilowatt-hours (1 unit = 1 kWh) and estimate your bill cost from units consumed and your per-unit tariff.
  • Monthly Electricity Cost from Watts Calculator
    Calculate the monthly electricity cost of any device from its wattage, daily usage hours and your per-kWh rate. Get daily, monthly and yearly estimates.
  • Motor Torque from kW and RPM Calculator
    Calculate electric motor torque in newton-metres from power (kW) and speed (RPM) using T = 9549 x kW / RPM. Includes lb-ft conversion.
  • Battery Discharge Time Calculator
    Estimate how long a battery will last from its amp-hour capacity, load current, and usable depth of discharge. Free runtime calculator: t = (Ah × DoD) / A.
  • kWh from Amps, Volts and Hours Calculator
    Calculate electricity usage in kWh from amps, volts and hours. Enter current, voltage and run time to get energy used, power in watts and cost.
  • Electricity Bill Calculator
    Estimate your electricity bill from units consumed (kWh), the per-unit rate, and any fixed charge. Free, fast, and works with any currency.
  • Power from Torque and RPM Calculator
    Calculate mechanical power in kW, watts and horsepower from torque (N·m) and rotational speed (RPM) using P = T × RPM / 9549.
  • Time to Fill Tank Calculator
    Calculate how long it takes to fill a tank from its volume and water flow rate using t = V / Q. Supports liters, gallons, m3, and multiple flow units.
  • Gas Density Calculator
    Calculate the density of an ideal gas from pressure, molar mass, and temperature using ρ = PM/(RT). Free, instant results in kg/m³ and g/L.
  • EV vs Gas Cost per Mile Calculator
    Compare the cost per mile of driving an electric vehicle versus a gas car. Enter kWh/mile, electricity price, gas price, and MPG to see your savings.
  • 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.

Categories