Physics and Engineering

  • Bucket Volume Calculator
    Calculate the volume of a tapered bucket from its top diameter, bottom diameter and height. Get results in liters, US gallons and UK gallons instantly.
  • Hot Tub Volume Calculator
    Calculate how many gallons of water your hot tub holds. Enter the shape and dimensions to estimate volume in gallons, liters and cubic feet.
  • Horizontal Cylindrical Tank Volume Calculator
    Calculate the liquid volume in a horizontal cylindrical tank for any fill height. Get partial-fill volume, fill %, liters and US gallons instantly.
  • Oval (Stadium) Tank Volume Calculator
    Calculate the volume of an oval (stadium / capsule cross-section) tank from its width, height and length. Get liters, cm³ and US gallons instantly.
  • Solar Panel Payback Period Calculator
    Calculate how many years it takes for solar panels to pay for themselves based on system cost, annual energy output, and your electricity price.
  • Pounds to Gallons Calculator (Water)
    Convert pounds of water to US gallons instantly. Enter the weight in pounds and get the volume using the standard 8.34 lb per gallon factor.
  • Head to Pressure Calculator
    Convert pump head (meters or feet) to pressure in PSI, kPa, bar and Pascals using P = ρgH. Supports any fluid specific gravity.
  • Mass Flow Rate Calculator
    Calculate mass flow rate (ṁ = ρAV) from fluid density, cross-sectional area, and flow velocity. Get kg/s and volumetric flow rate instantly.
  • Fluid Density Calculator
    Calculate fluid density from mass and volume using ρ = m / V. Get results in kg/m³ and g/cm³ instantly with this free density calculator.
  • Pump Power / Hydraulic Power Calculator
    Calculate pump shaft power and hydraulic power from flow rate, head, fluid density, gravity and efficiency. Get results in kW and HP instantly.
  • Manning's Equation Open Channel Flow Calculator
    Calculate open channel flow velocity and discharge with Manning's equation using roughness, area, wetted perimeter, and slope (SI units, m³/s).
  • Capillary Rise Calculator
    Calculate capillary rise height in a thin tube using Jurin's Law from surface tension, contact angle, liquid density, tube radius and gravity.
  • Horsepower to Watts Calculator
    Convert horsepower (HP) to watts (W) instantly. Enter mechanical horsepower and get the equivalent power in watts and kilowatts using W = HP × 745.7.
  • Watts to Horsepower Calculator
    Convert watts (W) to horsepower (HP) instantly. Supports mechanical, metric, and electric horsepower with the formula HP = W / 745.7.
  • Energy Cost per kWh Calculator
    Find your electricity rate per kWh by dividing your total bill by the energy used. Quick kWh cost calculator with cents-per-kWh output.
  • Amps to Kilowatts Calculator
    Convert amps (A) to kilowatts (kW) for DC, single-phase and three-phase AC. Enter current, voltage and power factor to get real power instantly.
  • Perfectly Inelastic Collision Calculator
    Calculate the final common velocity, total momentum, and kinetic energy lost in a perfectly inelastic collision where two objects stick together.
  • Power from Force and Velocity Calculator
    Calculate mechanical power from force, velocity and angle using P = F·v·cos θ. Get results in watts, kilowatts and horsepower instantly.
  • Watts to kWh Calculator
    Convert watts to kilowatt-hours (kWh) instantly. Enter the power in watts and running time in hours to find total energy use for any appliance.
  • Light Bulb Energy Cost Calculator
    Calculate the yearly, monthly and daily electricity cost of running a light bulb from its wattage, hours used per day and your price per kWh.
  • Inverse Square Law Light Intensity Calculator
    Calculate light intensity at a new distance using the inverse square law E₂ = E₁ × (d₁/d₂)². Free physics & lighting tool for lux and illuminance.
  • Server Power Consumption Cost Calculator
    Calculate the monthly and yearly electricity cost of running servers 24/7. Enter watts, price per kWh and server count to estimate power expenses.
  • PC Power Supply (PSU) Wattage Calculator
    Estimate the right PSU wattage for your PC build. Add CPU, GPU, RAM, storage and fans to get a recommended power supply size with 20% headroom.
  • dBm to Watts Calculator
    Convert dBm to watts and milliwatts instantly. Enter a power level in dBm to get the equivalent power in W using P = 10^((dBm−30)/10).

Categories