Servo torque question

I'm planning to build a robotic arm and need to know what servos to use.
Can someone tell me if my math is correct here?

When i take a servo that has a torque of 240 oz-in (17 kg-cm) and use that as shoulder joint.
A 20 cm long arm would be able to lift a maximum of 17 / 20 = 0.85 kg ?