check the dimensions.

Convert between units, parse a unit expression into its SI base dimensions, or check that an equation is dimensionally homogeneous. UnitDimCheck reduces any unit to exact rational exponents over the seven SI base dimensions (mass, length, time, current, temperature, amount, luminous intensity) — so it catches F = m·a (consistent) versus a wrong F = m·v (mass·length·time⁻¹ ≠ force) before any number is plugged in. The cheapest correctness check in physical science.