Physics Unit Converter

Force conversions use fixed ratios relative to the Newton (N), the SI unit. 1 pound-force (lbf) = 4.448 N, and 1 kilogram-force (kgf) = 9.807 N. Pick your source and target units and the converter applies the ratio instantly — no manual maths.

They all measure energy but at very different scales. 1 calorie = 4.184 J, 1 BTU ≈ 1055 J, and 1 kilowatt-hour (kWh) = 3,600,000 J. kWh is used for electricity billing, calories for food/heat, and BTU for heating and cooling systems.

All speeds convert through metres per second (m/s). 1 km/h = 0.2778 m/s, 1 mph = 0.4470 m/s, and 1 knot = 0.5144 m/s. So 100 km/h ≈ 27.8 m/s ≈ 62 mph.

It converts between Watts (W), kilowatts (kW), horsepower (hp), and BTU per hour. 1 hp ≈ 745.7 W and 1 kW ≈ 3412 BTU/hr. Power is the rate of energy transfer — energy per unit time.

The SI-defined ratios (e.g. 1 kWh = 3.6 MJ) are exact; a few (like horsepower and BTU) have standard rounded definitions used consistently here. Results are accurate for engineering, physics homework, and everyday use.