Physics Calculators

Open a focused SI calculator and see the formula, inputs, worked example and limits before using the result.

Available tools

  • Speed Calculator — Calculate average speed from distance and time with v = d / t, with the result in m/s and km/h and a worked sprint example.
  • Force Calculator — Calculate net force from mass and acceleration with Newton's second law, F = m × a, in newtons, with a worked example and limits.
  • Kinetic Energy Calculator — Calculate kinetic energy from mass and speed with E = ½mv², in joules, with a worked example and the classical-mechanics limits.

Using these tools

Use consistent SI inputs and treat each result as a calculation check. More complex systems may require vector analysis, uncertainty analysis or professional review.

One example, three calculators

A 1,200 kg car accelerates from rest to 100 km/h (27.78 m/s) in 10 seconds. The three tools on this page describe the same event from different angles:

QuantityFormulaResult
Average speed during the runv = d / t (here (0 + v) / 2)13.89 m/s, covering 139 m
Average accelerationa = Δv / t2.78 m/s²
Net force neededF = m × a3,333 N
Kinetic energy at 100 km/hE = ½ m v²463 kJ

Every calculator works in SI units: metres, kilograms and seconds. Convert km/h to m/s by dividing by 3.6 and grams to kilograms by dividing by 1,000 before entering values; for other units use the speed and energy converters.