What Size Do You Need?
Last verified: September 2026
Everything you actually need to know, in plain English - no jargon, no rabbit holes. If you'd rather skip the reading and just have someone help, my number is (330) 200-8042.
What Size Do You Need?
Sizing an inverter generator sounds like math, but it really comes down to a friendly, step-by-step process: make a short list of what you truly want to keep running, add up their steady watts, add the single biggest motor surge on top, and leave a little headroom. Do that and you'll buy the right size the first time — usually smaller and cheaper than you feared. Here's the plain-English walk-through, with a printable, 29-page guide up top if you'd like the full version.
Common Questions
1 How do I figure out what size generator I need?
Start with a short must-run list — the few things you'd truly want in an outage, not the whole house. Add up their steady running watts, then add the single biggest motor surge (the fridge or furnace fan kicking on) on top. Leave a little headroom, and that total is your size. Most folks land smaller than they expect.
2 What's the difference between running watts and starting watts?
Running watts is the steady amount a device sips while it's on. Starting watts is a brief extra gulp that anything with a motor — a fridge, a pump, a furnace fan — grabs for the first second when it kicks on, often several times its running number for just a heartbeat. Lights and electronics barely surge at all.
3 Do I add up the starting surge of everything?
No — and this is the mistake that makes people overbuy. You add only the single biggest surge, once, on top of your running total. Motors almost never start at the very same instant, so there's no need to stack every surge. Plan for the largest one and you're covered.
4 Isn't a bigger generator always safer?
Usually not. An oversized unit is heavier to move, thirstier on fuel, and costs more up front for watts you'll never use. A right-sized generator with a sensible cushion of headroom is the smarter, easier-to-live-with choice — light enough to wheel out, quiet enough to run in eco mode, and big enough for your list.
5 What size do I need for a well pump?
Most home well pumps run on 240 volts with a big start-up surge, so the small, quiet 120-volt units can't run them at all. As a general guide, a common half- to one-horsepower pump often wants a 120/240-volt generator in roughly the 4,000-to-5,000-watt class, and a bigger pump wants more. A soft-start device can lower the surge, and an electrician handles the hookup. Have your pump checked to size it right.
6 Can you help me figure out my size?
Gladly. Make your must-run list and jot down the watts you can find, then give me a call. We'll work through the numbers together, land on the right size class, and make sure anything involving 240 volts or your home's wiring gets a licensed electrician. One friendly point of contact for the whole thing.
Want a Hand With Yours?
Picking a generator, setting it up, and learning to run it safely is one of my most-requested visits. I bring the patience and the know-how - you keep your seat. We'll match a unit to your home, set it up right, walk through starting it and staying safe from carbon monoxide, and get your internet, TV, and devices happily back on. $99 flat, and every visit is 30-day come-back-free. (330) 200-8042.
Would you rather I just do this for you?
No shame in it — plenty of folks would rather hand it off, and that's what I'm here for. I'll come to your home, set it up right, and make sure it's working before I leave. Flat $99 per visit — no jargon, no upsell, and every visit is 30-day come-back-free.
Not a hardware job? I can often fix it remotely for $49 — a secure screen-share, up to 2 hours, that you watch the whole time and can end whenever (included free for $39/mo Support Plan members, and it counts toward the $99 if it turns out I need to come out).