The box says
“13,000 watts”
Peak — held for seconds
Generators are sold on peak watts — a surge they hold for seconds. We rank them by cost per running watt, the power they actually deliver all day, and show noise, runtime and power quality beside it — plus each model’s CO-shutoff record.
Four numbers decide the ranking — the same four for every generator, so the comparison is honest. A maker that doesn’t publish all four doesn’t get ranked.
Street price divided by continuous running watts — not the peak number. The headline value; lower is better.
The maker’s rated dBA. Every 10 dBA is roughly twice as loud — it decides whether neighbours (or campsites) tolerate it.
Hours on one tank at the published 25–50% load — how often you’re refuelling through an outage.
Inverters produce clean, stable power (low harmonic distortion) that’s safe for laptops, phones and modern electronics. Conventional units don’t.
Showing … portable generators · lower cost per running watt is better · prices last reviewed 2026-07
As an Amazon Associate we earn from qualifying purchases, at no extra cost to you — commission never changes a ranking or a verdict (how this site is funded).
| # | Generator | $ / running W | Running / peak | Noise | Runtime | Type | Shop |
|---|---|---|---|---|---|---|---|
| 1 | Gas · conventional | $0.12 | 9,500 W peak 12,500 W | 74 dBA | 8 h @ 50% | Conventional | Amazon ↗ |
| 2 | Dual fuel · conventional | $0.12 | 10,500 W peak 13,000 W | 74 dBA | 8 h @ 50% | Conventional | Amazon ↗ |
| 3 | Dual fuel · conventional | $0.14 | 4,500 W peak 5,500 W | 69 dBA | 9 h @ 50% | Conventional | Amazon ↗ |
| 4 | Dual fuel · conventional | $0.19 | 3,800 W peak 4,750 W | 68 dBA | 14 h @ 50% | Conventional | Amazon ↗ |
| 5 | Gas · inverter | $0.27 | 3,000 W peak 3,500 W | 56 dBA | 11 h @ 25% | Inverter | Harbor Freight ↗ |
| 6 | Gas · inverter | $0.27 | 1,900 W peak 2,350 W | 51 dBA | 5.7 h @ 50% | Inverter | Amazon ↗ |
| 7 | Gas · inverter | $0.28 | 3,900 W peak 5,000 W | 52 dBA | 18 h @ 25% | Inverter | Amazon ↗ |
| 8 | Gas · inverter | $0.28 | 3,000 W peak 4,000 W | 64 dBA | 10 h @ 25% | Inverter | Amazon ↗ |
| 9 | Gas · inverter | $0.32 | 1,800 W peak 2,200 W | 52 dBA | 12 h @ 25% | Inverter | Amazon ↗ |
| 10 | Gas · inverter | $0.61 | 1,800 W peak 2,200 W | 57 dBA | 8.1 h @ 25% | Inverter | Amazon ↗ |
$ / running W = price ÷ continuous running watts (the wattage the unit sustains, not the brief peak/starting surge). Running / peak shows both so you can see the gap. Noise is the manufacturer’s rated dBA — measurement conditions differ by brand; hover a pill for the maker’s stated conditions. Runtime is one tank at the published load, shown per row. Inverter units deliver clean power (typically < 3% THD) safe for electronics. The CO note under each name records that exact SKU’s shutoff status — who stands behind each system. Every spec traces to the maker’s published page; prices drift — the linked listing is authoritative. Some product links are affiliate links; they never change a ranking. As an Amazon Associate we earn from qualifying purchases. Generac’s GP series publishes watts and runtime but no noise spec, so it isn’t ranked —
Solar “generators” are lithium battery power stations. They’re silent and clean, but they don’t generate anything — capacity is fixed until you recharge, and sustained high-draw output is limited. Useful, but not comparable per running watt, so we keep them separate.
The ranking tells you what a watt costs. The CO-shutoff record tells you who stands behind each machine’s safety system — the question that should be on every listing.