Some servo manufacturers use ounce-inches (oz-in), others use kilogram-centimetres (kg-cm). The correct SI units are milliNewton-metres (mNm) which is the same as Newton-millimetres (Nmm).
Just type a torque value into one of the boxes and click on the "Solve Others" button. The calculator will then fill in the equivalent values for you. This should be useful when you are trying to compare servos from different manufacturers.
To calculate the force at a distance from the servo, type the distance in the box below and click on the "Calculate" button.
kgf means "kilograms force", used to distinguish it from kg meaning "kilograms mass".
The calculator will open in a new window or tab so you can keep it handy while you browse for servos :)