Transmission fluid

I have a 96 Grand AM its a 3.1 and i just did the transmission filter and fluid....i dont have a clue on how much fluid to put back in .....a friend said 4 qts but i want to make sure before i start driving around.....thanks

Start the vehichle and let it IDLE for 5 minutes. Move the transmission from Park to Reverse to Neutral to Drive, 2, 3 and then back to 2 to Drive to Neutral to Reverse to Park. Let the vehicle still run at IDLE and then pull the transmission dipstick and measure. Add some fluid until it reaches the max line. Put back the dipstick and drive the vehicle around the block a couple of times and then bring it home and measure the transmission level while the engine is still running at IDLE.