Or have you?

Yet Another Unit Converter converts between lots of units, including metric and Imperial.

But Yet Another supports more than 561 units (and nearly every letter of the alphabet!) for acceleration, angle, angular acceleration, angular velocity, area, capacitance, charge, current, dynamic viscosity, energy, force, inductance, kinematic viscosity, length, magnetic flux, mass, power, pressure and SI prefixes.

But hold on. Yet Another Unit Converter also supports conversions for solid angle, specific heat, speed, temperature, thermal conductivity, time, velocity, voltage, volume and weight.

Phew!