Residential Electrical Load Calculator
Estimate your home's electrical load per NEC 2020. Includes lighting, appliances, HVAC, and demand factors. Get a printable PDF report for permits.
✅ Free · No signup · No email required📊 Data from public industry sources🕐 Prices updated June 2026🔒 We never see your data🧑💻 Built by AmpFlow · About us
Calculate Your Home's Electrical Load in Minutes
📊 Data sourced from publicly available industry standards. See our methodology page for formulas, sources, and limitations.
You're here because you need to size a service panel, check if your existing setup can handle a new appliance, or pull a permit. I've been there — when I moved into my 1950s house, the 60-amp service couldn't even run the microwave and lights at the same time. This calculator follows the National Electrical Code (NEC) 2020, specifically Tables 220.12, 220.55, and 220.54. Just enter your square footage, pick your appliances, and we'll do the rest. No email required, no signup. Based on real data from the U.S. Energy Information Administration and the Department of Energy.Why Use This Calculator vs. Other Tools
Most free load calculators online are garbage. They give you a single number with no breakdown. Here's how ours stacks up:
**Input Fields:** We include 10+ adjustable parameters. Others often skip the electric heating load or heat pump.
**NEC Compliance:** We use the actual demand factors from the code. Many tools just multiply everything by 0.8.
**Printable Report:** You get a PDF summary for permit applications. That's a game-changer for contractors.
**Speed:** No account, no email. Fill it in under 2 minutes.
Honestly, this won't work if your home has non-standard appliances like a commercial-grade range or a 3-phase service. But for 95% of residential jobs, it's spot on.
How to Use the Results for Your Permit or Panel Upgrade
Once you've run the calculator, here's what to do next:
1. **Check against your existing service size.** If your calculated load exceeds the panel rating (e.g., 150 amps on a 100-amp panel), you need an upgrade.
2. **Print the report.** Most building departments require a load calculation sheet. Our PDF includes the NEC references.
3. **Talk to an electrician.** They'll verify your specific wire sizes, breakers, and local code amendments.
In my experience, the biggest gotcha is electric heating. If you have baseboard heaters, the load jumps fast — 12 W/sq ft adds up. Also, don't forget to include both AC and heat pump if you have a dual-fuel system. The code says you only count the larger of heating or cooling, but the calculator handles that automatically.
Frequently Asked Questions
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Frequently Asked Questions
- What is a residential electrical load calculation?
- It's the process of adding up all electrical loads in your home — lights, appliances, HVAC, water heater — to determine the minimum panel size you need. It's required for permits, panel upgrades, and new builds per NEC Article 220.
- How do I know if my panel is oversized or undersized?
- If your main breaker trips when running the AC and dryer at the same time, your panel is likely undersized. If you have a 200A panel but the calculator shows only 80A of load, it may be oversized. Our calculator shows your calculated load vs. recommended panel size.
- Is this calculator free? No email required?
- Yes. No email, no signup. Just enter your appliances and get the load calculation instantly.
- Can I use this for a permit application?
- This calculator follows NEC Article 220 methodology and provides a reasonable estimate. Most jurisdictions require a licensed electrician's signed load calculation for permits. Use our result as a starting point, but get a pro to finalize for your permit application.
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