The answer to 'what size circuit breaker do I need' is that the size of the circuit breaker you need depends on the electrical load and wiring of the circuit it will be protecting. As a general rule, the circuit breaker should be sized to handle 125% of the maximum expected electrical load on the circuit. This ensures the breaker will trip before the wiring overheats and becomes a fire hazard.
To determine the right size circuit breaker, you'll need to know the total wattage or amperage of the electrical devices and appliances on the circuit. Then, you can consult electrical codes and guidelines to select the appropriately sized breaker, typically ranging from 15 to 50 amps. It's best to consult a licensed electrician to ensure you choose the right breaker for your home's electrical system.