What Size Electrical Panel Do I Need for My House?

How to Choose the Right Electrical Panel Size for Your Home

Choosing the right size electrical panel for your home isn’t just about convenience—it’s about safety, efficiency, and protecting your biggest investment. At Root Electric, we’ve been helping Northern Virginia homeowners with electrical panel upgrades and replacements since 1986. Whether you’re adding a home office, upgrading to an EV charger, or simply tired of tripped breakers, knowing what size panel you need is the first step toward a safe and future-proof electrical system.

In this guide, we’ll walk you through everything you need to know about electrical panel sizing, when to consider a replacement, what it costs, and how our licensed electricians can help.

🏡 Why Electrical Panel Size Matters for Your Home

Your home’s electrical panel—sometimes called a breaker box—acts as the central hub for all your electricity. It distributes power to every outlet, appliance, and device. But if your panel is too small for your household’s needs, you could face:

• Constantly tripping breakers
• Limited ability to add new appliances or upgrades
• Increased fire risks due to overloaded circuits

Most older homes still have 100-amp panels, which were standard decades ago. But today, with modern appliances, smart devices, and EV chargers, many households need 200 amps or even more.

Our experienced team at Root Electric can assess your system and determine whether you need an electrical panel upgrade for safety and efficiency.

⚙️ Common Electrical Panel Sizes Explained

Homeowners often ask: “What’s the difference between a 100-amp and a 200-amp panel?” Here’s a simple breakdown:

• 100-Amp Panels – These are found mostly in homes up into the early 1960's. They were most commonly installed in homes before central A/C became popular. 100 Amp services are adequate for small homes, and may support A/C with gas heat and gas appliances. This type of service will typically not support a heat pump or electric vehicle charging equipment.
• 150-Amp Panels – These are found mostly in homes up into the mid 1970's. 150 Amp panels typically feature "split buss" architecture, which is a design where there is no defined "main breaker". Whereas a main breaker load center can be completely shut down with one throw of the hand, a split buss load center will require up to six breakers to be shut down to cut power to the entire house. Split buss panels were adequate for their time but contain an inherent "bottle neck" that can cause them to be overloaded without actually overloading the 150 Amp service. These panels can support homes with central A/C with mixed gas and electric appliances. A 150 Amp service may support electric vehicle charging equipment, depending on the type and number of major appliances.
• 200-Amp Panels – This is the most commonly installed load center for homes built from the mid 1970's until today. With very few exceptions, 200 Amp load centers are "main breaker" style, where there is one main switch that can cut or supply power to the entire electrical panel. 200 Amp panels can support homes with central A/C and mixed-gas and electric appliances or homes with all electric appliances with up to one heat pump. Homes with 200 Amp services and gas heat can easily support electric vehicle charging equipment, as long as no more than one vehicle charging connector is installed. Where there is a 200 Amp panel, a heat pump, and all electric appliances, electric vehicle charging can be supported in a case-by-case basis. It is recommended that a professional electrician performs load calculations before installing EV charging equipment on a home with a 200 Amp service and all electric appliances.
• 400-Amp Panels – There is actually no such thing as a 400 Amp electrical panel for residential applications. Homes with a 400 Amp service feature two separate 200 Amp load centers. If installed properly, circuits for the home's systems are evenly distributed between both panels so that each 200 Amp panel has a roughly equal share of the load. 400 Amp services can support homes with up to two heat pumps and all electric appliances. Depending on the mix of gas vs. electric appliances, a 400 Amp service can provide power for up to two EV wall connectors.

When you schedule an electrical inspection, our team will review your household’s power usage and recommend the safest and most cost-effective option for your needs.

💡 Signs You May Need an Electrical Panel Upgrade

Not sure if your current system is keeping up? Here are some common warning signs:

• Flickering lights when appliances turn on
• A warm or buzzing breaker panel
• Using too many power strips or extension cords
• Constantly tripping breakers
• An outdated fuse box instead of a modern breaker panel

If you notice any of these, it’s time to consider a home electrical panel upgrade. Root Electric specializes in electrical panel replacement services designed to bring your home up to modern standards.

💲 Electrical Panel Upgrade Costs: What to Expect

Cost is one of the biggest concerns for homeowners. While every project is different, here are general guidelines:

• Electrical Box Upgrade (100 to 200 amps): Typically required when expanding household needs
• Breaker Panel Replacement: Common for older homes with outdated systems
• Electrical Panel Update (for remodels or heavy appliances): Necessary when upgrading kitchens, HVAC, or EV charging stations

Several factors affect your cost, including:

• Age and condition of your home’s wiring
• Location of your panel (basement, garage, outdoors)
• Whether your utility company requires meter upgrades

At Root Electric, we provide transparent estimates and walk you through every step before work begins. No surprises, just honest service.

🔧 Professional Electrical Panel Upgrade Service

Attempting a DIY electrical panel replacement is dangerous and not recommended. Hiring licensed professionals ensures:

• Correct sizing and installation to prevent overloads
• Compliance with local building codes and safety standards
• Long-term peace of mind with reliable performance

Our Master and Journeyman electricians at Root Electric bring decades of experience. Every job is handled with a safety-first mindset, ensuring your home is protected from electrical hazards.

👉 Interested in EV charging station for your home? Read our guide on licensed electricians for EV charger installation.

🏘️ Future-Proofing Your Home with a Panel Upgrade

Think about your home five or ten years from now. Will you want:

• An electric vehicle charging station?
• A home office with multiple computers?
• A finished basement or addition?
• Smart appliances and solar integration?

Upgrading your electrical panel today helps you prepare for tomorrow’s needs. It also boosts resale value since buyers prefer homes already equipped with modern breaker panels.

❓ FAQ: Electrical Panel Upgrades for Homeowners

Here are some of the most common questions we hear from customers:

Q: How do I know what size electrical panel my house needs?
A: Most modern homes require at least 200 amps, but it depends on your square footage, appliances, and future plans. Our electricians perform a load calculation to give you the right answer.

Q: How long does an electrical panel replacement take?
A: Usually 4–8 hours. For larger upgrades or complicated wiring, it may take longer.

Q: Do I need a permit for an electrical panel upgrade?
A: Yes. Root Electric handles all necessary permits and inspections to ensure your upgrade meets code.

Q: Can I replace my breaker box myself?
A: No. Electrical work can be extremely hazardous. Always hire licensed professionals like Root Electric for this type of project.

Q: What’s the lifespan of an electrical panel?
A: Most panels last 25–30 years. If yours is older, it may be time for an upgrade.

📞 Call Root Electric for Electrical Panel Upgrade Service

Your electrical panel is the heart of your home’s power system—don’t leave it to chance. If you’re unsure whether your house needs a breaker panel replacement or just an inspection, Root Electric is here to help.

With over 35 years of experience serving Northern Virginia homeowners, we’ve built our reputation on safety, reliability, and customer satisfaction. From small repairs to complete home electrical panel upgrades, we’ve got you covered.

👉 Call us today at (703) 494-3989 or contact us online to schedule your electrical panel upgrade service. Let’s make your home safe, efficient, and ready for the future.