A modern NEC-compliant home typically needs: 2,000 sqft / 3 bed / 2 bath: 18–22 circuits; 2,800 sqft / 4 bed / 3 bath: 24–30 circuits; 3,500+ sqft / 5 bed / 4 bath: 32–42 circuits. These counts include NEC-mandated dedicated circuits (kitchen small. Example: Need a circuit for your 1,800W microwave? Calculator Tip: Tools like Desmos' scientific calculator make light work of conversions. Just plug in your wattage and voltage—let it handle the decimals. You're not just calculating numbers—you're designing a system that matches how you live. You lower the chance of circuits getting too hot or overloaded when you pick the right box for your needs. How many groups should I choose for my distribution box? When choosing a distribution box, the number of groups depends on your electrical appliances and future expansions.
[PDF Version]