For 20 AMP you have 20A*120V or 2400 watts and 15 AMP you have 15A*120V or 1800 watts. Good Electricians will only plan for 80% load so you have 1920 and 1440 watts respectively at your disposal per circuit. Next, find out what's on the circuit. To do this, leave the lights on that you want to connect to.
Also, how far apart do you put LED downlights?
Spacing. Recessed downlights are generally positioned 1.5 to 2 ft. away from walls with a space of 3 to 4 feet between each light. Dividing the ceiling height by two is a way of gauging how much space to leave between each downlight. Thus, if your ceiling is 8 foot high, place your lights 4 feet apart.
How far apart do you put landscape lights?
As a Rule of Thumb, Space Lights Every Six to Eight Feet. As a general rule, plan on placing lights six to eight feet apart to keep your pathway bright and well-lit.
How many can lights do I need in a bedroom?
The typical rule-of-thumb is 24" from each wall, and then 3-5 feet between cans. So in a 12' room you'd probably want two rows of lights. Considering it is a bedroom and you don't need it as bright as a kitchen, you can probably get away with 2 rows of 4 lights for a total of 8.