How to calculate how much weight my servo can handle?

I have a Tower Pro 9g Micro Servo (SG90) and it's datasheet says it's stall torque is (Stall Torque at 4.8 volts = 16.7 oz/in (1.2 kg/cm)), but as I haven't learned physics, I don't know how to calculate how much weight it can handle stacked on top of the arm/horn. I have googled torque calculations and the servo itself, but can't seem to find an answer to my question.

Thank you for any help you can provide me, I appreciate your time.


torque is mesured in in pous

torque is mesured in in pous ir foot punds (or the metric equivilant)

10 foot pound or tourq ecentialy means 10 pound one fot away from pivit.  (or 1 pound 10 feet away, same thing)

Your distance is 1 inch.  your weght is 16.7 oz.  (about a pound)

This means at on inch away you can do just about a pound of weight.  at 2, half a pound.  4 quarter pound.  10 inches, 1/10th pound.


Usually the stall torque
Usually the stall torque measurement is under some sort of ideal conditions, so I’d halve the number.

So if the company says 1.2 kg-cm, I would assume 0.6 kg-cm is the amount of torque it will give a stall from a static position.

And torque can be measured with any units of force-distance. For certain applications, certain units are called for, but generally for hobby motors companies use whatever they use.

depends on brand, we tested

depends on brand, we tested servoes for airplane use and all got to withing 5% of stated value.  Some got as high as an extra 15%.  We tested before the build so we knew we wouldnt have any trouble in the air.

I’ve not had that much luck,
I’ve not had that much luck, even with expensive servos.

The static stall torque usually was much less than the dynamic stall torque.