Choose your channel below
As a leading wholesaler of home inverters, we understand that your success depends on providing the right product for your customers. One of the most common and critical questions from end users is: “What size inverter do I need to run my house?”
For us, as dealer partners, the answer is more than just a number—it’s about understanding the application, managing customer expectations, and stocking the right inverters to meet market demand.
This guide details the home inverter selection process, empowering you with the knowledge to advise your retail customers and ensure they source the most appropriate product from your inventory.
In short: There’s no one-size-fits-all solution.
The inverter capacity required to run a whole house ranges from 3kW (3000W) for baseload to 10kW (10,000W) or more for whole-house backup. The key is matching the inverter size to the specific power needs of the home.
Step-by-Step Guide: How to Calculate Inverter Size
Guide your customers through this simple three-step process. This will prevent both undersizing the inverter (causing overloads and shutdowns) and oversizing it (causing unnecessary costs).
Step 1: Create a load list
The first step is to list all appliances that the homeowner plans to run simultaneously during the power outage. It’s crucial that they record both the running power (the power required to keep the appliances running) and the starting/inrush power (the brief amount of power required to start the motors in appliances like refrigerators, air conditioners, and water pumps).
| Common Appliance | Running Watts | Starting/Surge Watts |
| Refrigerator | 150-800 | 500-2200 |
| LED Light Bulb | 5-20 | 0 |
| Ceiling Fan | 20-75 | 0 |
| Water Pump | 750-1500 | 1500-3000 |
| Television | 100-400 | 0 |
| Laptop | 50-100 | 0 |
| Window AC (1 Ton) | 1500-2000 | 2200-3500 |
| Sump Pump | 1000 – 1500 | 2000-3500 |
| Microwave | 800-1500 | 0 |
Step 2: Calculation
Calculate the total operating power: Add the operating power of all appliances that are turned on simultaneously.
Determine the highest starting power: Find the highest starting power from the list. Do not add all starting powers together.
Calculate the total power required: The inverter must be able to handle:
Total power required = Total operating power + Maximum starting power
Step 3: Add a safety margin
It’s always wise to add a 20-25% safety margin to the total power required. This allows for future appliance additions and ensures the inverter isn’t constantly running at maximum power, extending its lifespan.
Calculation example:
Appliances (running simultaneously): Refrigerator (700W), 10 LED lights (150W), TV (200W), water pump (1200W), ceiling fan (50W).
Total operating power: 700 + 150 + 200 + 1200 + 50 = 2300W
Maximum starting power: The water pump’s surge power is 2800W.
Total power required: 2300W + 2800W = 5100W
20% safety margin: 5100W x 1.20 = 6120W
In this case, the homeowner needs an inverter rated at at least 6200W to 6500W.
Common Home Scenarios and Recommended Inverter Sizes
To help guide your customers, here are typical usage scenarios and the inverter capacities you should stock:
Basic Circuits Only (3kW – 5kW):
Covered by: Lights, fans, TVs, computers, refrigerators, WiFi routers.
Ideal for: Customers seeking a basic, cost-effective backup solution. This is a high-capacity market segment.
Medium Home (5kW – 8kW):
Covered by: All essentials, plus a water pump, a small air conditioner (1 ton), and a microwave oven (one in use at a time).
Ideal Use: Most medium-sized homes requiring comfortable backup power. This is your core product line.
Whole-House Backup Power (8kW – 15kW+):
Covered: Powering nearly the entire house, including multiple air conditioners, well pumps, and kitchen appliances.
Ideal Uses: High-end residential projects, large residences, and areas with frequent and prolonged power outages.
Key Customer Considerations
Pure Sine Wave vs. Modified Sine Wave: Pure sine wave inverters are always recommended for home use. They are compatible with all modern electronic devices (such as laptops, medical devices, and variable-speed motors) and are more efficient and safer. This is a key value-added service you can offer.
Inverter vs. Inverter/Charger Combo: Most whole-house systems are actually inverter/chargers. They not only convert DC power to AC power but also manage battery charging from the grid or solar panels. Make sure your product line includes these integrated units.
Battery Bank Capacity: The size of the inverter determines the power you can run, while the battery bank’s capacity (measured in ampere-hours) determines its lifespan. This is a separate but critical component of the system you offer.
Partner with an Experienced Wholesaler
Correctly sizing your inverter is the first step to satisfying your end customer. As your trusted wholesale partner, Enernova offers a wide variety of reliable, efficient pure sine wave inverters—ranging from 2kW to 20kW—as well as the technical support and market knowledge you need for success.
Stock the right solutions. Contact us today to discuss your inventory needs and let us help your business grow.
