Physics and Engineering

  • kWh to CO2 Emissions Calculator
    Convert electricity use (kWh) to CO2 emissions in kilograms using your grid emission factor. Free, instant kWh to kg CO2 calculator.
  • Power Station Runtime Calculator
    Estimate how long a portable power station or battery (in watt-hours) will run a device. Enter capacity, load watts and efficiency to get runtime in hours.
  • Low Voltage Wire Voltage Drop Calculator
    Calculate voltage drop in low-voltage wiring for LED, landscape & 12V/24V DC systems. Enter current, wire length and AWG gauge to size your cable.
  • Electricity Carbon Footprint Calculator
    Calculate the COā‚‚ carbon footprint of your electricity use from kWh and your grid emission factor (kg COā‚‚/kWh), per period and total.
  • Weight Calculator (W = mĀ·g)
    Calculate weight as a force in newtons from mass and gravitational acceleration using W = mĀ·g. Free, instant, and works for any planet's gravity.
  • Magnification Calculator
    Calculate optical magnification of a lens or mirror from object and image distances using M = -di/do. Shows magnitude, orientation, and image type.
  • Critical Angle Calculator
    Calculate the critical angle for total internal reflection from two refractive indices using Īøc = arcsin(nā‚‚/nā‚). Free, fast and accurate.
  • Sound Intensity Level Calculator
    Calculate sound intensity level in decibels (dB) from sound intensity using L = 10Ā·log10(I/I0) with the standard reference 1e-12 W/mĀ².
  • Three-Phase Power Calculator
    Calculate three-phase active, apparent and reactive power from line voltage, line current and power factor using P = āˆš3Ā·VĀ·IĀ·cos Ļ†.
  • Rectangular Pool Volume Calculator
    Calculate how many gallons of water your rectangular pool holds. Enter length, width, and average depth in feet to get the volume instantly.
  • Rectangle Area Moment of Inertia Calculator
    Calculate the area moment of inertia (Ix and Iy) of a rectangular cross-section about its centroidal axes from width and height.
  • Final Temperature of Mixing Two Liquids Calculator
    Calculate the final equilibrium temperature when two liquids (such as water) of different masses, specific heats, and temperatures are mixed together.
  • Specific Heat Capacity Calculator
    Calculate specific heat capacity from heat energy, mass and temperature change using c = Q / (mĀ·Ī”T). Fast, accurate physics tool with worked example.
  • Heat Transfer Rate Calculator
    Calculate heat energy transferred (Q = mcĪ”T) from mass, specific heat, and temperature change. Free physics calculator with joules and kilojoules output.
  • VinFast Monthly Charging Budget Calculator
    Estimate your VinFast EV's monthly home-charging cost from miles driven, efficiency (mi/kWh), and your electricity rate. Includes yearly and per-mile costs.
  • VinFast VF3 Charging Cost Calculator
    Estimate the cost to charge a VinFast VF3 EV from your start to target state of charge using battery size, charging efficiency, and your electricity rate.
  • Lighting Watts to Amps Calculator
    Convert lighting watts to amps instantly. Enter total fixture wattage, voltage, and power factor to find the current draw for sizing circuits and breakers.
  • Lighting kWh Usage Calculator
    Calculate the kWh energy used by your lighting and its cost. Enter bulbs, watts, hours per day and days to estimate consumption and electricity bills.
  • Maximum Lights per Circuit Calculator
    Find how many light fixtures you can safely put on a circuit. Enter voltage, breaker amps and watts per fixture to get the max count at the 80% rule.
  • Pump Affinity Laws Calculator
    Use the pump affinity laws to find new flow, head, and power when impeller speed changes. Enter initial values and the new RPM to get instant results.
  • Pitot Tube Velocity Calculator
    Calculate fluid or airspeed velocity from a pitot tube's differential pressure and density using v = āˆš(2Ī”P/Ļ). Free, instant results in m/s, km/h, mph.
  • GPM to Pipe Velocity Calculator
    Convert flow rate (GPM) and pipe inside diameter to water velocity in ft/s. Uses v = 0.4085 Ɨ GPM Ć· dĀ² for fast, accurate pipe sizing.
  • Kinetic Friction Incline Acceleration Calculator
    Calculate the acceleration of a block sliding down a rough incline from angle, kinetic friction coefficient, and gravity using a = g(sinĪø āˆ’ Ī¼cosĪø).
  • Spring-Mass Oscillation Period Calculator
    Calculate the period, frequency and angular frequency of a mass on a spring using T = 2Ļ€āˆš(m/k). Free online simple harmonic motion calculator.

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