Load Assessment & Appliance Wattage Reference
Before you size a generator or batteries, you need to know one thing: what your home actually draws. This page helps you identify essential loads and understand realistic appliance wattage so your backup system is sized correctly.
What Is a Load Assessment?
A load assessment is the process of identifying which appliances and systems you plan to run during an outage and how much power they require — both continuously and at startup.
Appliance Wattage Reference (Typical)
| Appliance | Running Watts | Startup / Surge Watts |
|---|---|---|
| Refrigerator / Freezer | 600–800 W | 1,800–2,400 W |
| Sump Pump (1/2 HP) | 800–1,050 W | 2,000–3,000 W |
| Furnace Blower | 400–800 W | 1,200–1,800 W |
| Well Pump (1 HP) | 1,000–2,000 W | 3,000–5,000 W |
| Microwave | 1,000–1,500 W | ≈ same |
| LED Lighting (whole home) | 100–300 W | ≈ same |
| Modem + Router | 40–100 W | ≈ same |
| Medical Device (CPAP / concentrator) | 300–600 W | Varies |
Next Step: Total Your Loads
Once you know which appliances you must run, use the load calculator to total your running watts and identify your largest startup surge.
Open the Load Calculator →Load Assessment & Appliance Wattage Reference
Before you size a generator or batteries, you need to know one thing: what your home actually draws. This page helps you identify essential loads and understand realistic appliance wattage so your backup system is sized correctly.
What Is a Load Assessment?
A load assessment is the process of identifying which appliances and systems you plan to run during an outage and how much power they require — both continuously and at startup.
Appliance Wattage Reference (Typical)
| Appliance | Running Watts | Startup / Surge Watts |
|---|---|---|
| Refrigerator / Freezer | 600–800 W | 1,800–2,400 W |
| Sump Pump (1/2 HP) | 800–1,050 W | 2,000–3,000 W |
| Furnace Blower | 400–800 W | 1,200–1,800 W |
| Well Pump (1 HP) | 1,000–2,000 W | 3,000–5,000 W |
| Microwave | 1,000–1,500 W | ≈ same |
| LED Lighting (whole home) | 100–300 W | ≈ same |
| Modem + Router | 40–100 W | ≈ same |
| Medical Device (CPAP / concentrator) | 300–600 W | Varies |
Next Step: Total Your Loads
Use the quiz + practice tool below to build a realistic list, then open the full load calculator when ready.
Open the Load Calculator →Home Load Assessment Quiz (Interactive)
Answer each question to learn how to size backup power correctly. Instant feedback + live score.
Practice: Quick Load Assessment
Add only what you must run during an outage. We’ll total running watts and add the single largest startup surge.
| Item | Qty | Running (W) | Startup (W) | |
|---|---|---|---|---|
| Totals | 0 | 0 | 0 |
Tip: For motors (pumps, fridges, blower fans), startup watts often decide whether equipment will actually start. Always verify appliance nameplates before buying.
Next step: pick the right system
Now that you understand critical loads + startup surges, compare options that match your numbers.
Many homeowners use a combo: generator for big loads + UPS for modem/PC/medical continuity.