Physics calculators

Estimate appliance energy use and cost from power, daily runtime, days, and electricity rate.

Calculate voltage, current, resistance, and power from any two selected electrical values.

Decode a four-band resistor value from colour digits, multiplier, and tolerance.

Estimate two-conductor copper or aluminum circuit voltage drop from length, current, voltage, and wire area.

Calculate engine horsepower and kilowatts from torque and rotational speed.

Calculate mechanical horsepower and watts from force, travel distance, and elapsed time.

Calculate density from mass and volume, with common SI and metric conversions.

Calculate mass from density and volume, with grams, kilograms, and pounds.

Calculate speed from distance and time with km/h, m/s, mph, and pace conversions.

Calculate gravitational weight force from mass and local gravitational acceleration.

Calculate dew point and a plain-language humidity comfort description from temperature and relative humidity.

Estimate apparent temperature from air temperature and relative humidity with the NOAA regression.

Calculate the North American wind-chill index from air temperature and wind speed.