Best overall
Honda EU2200i
2,200W start · 1,800W run
Gasoline · Inverter · 48–57 dBA · 47 lb
The benchmark quiet inverter — legendary engine reliability and clean power (<3% THD) for sensitive electronics.
Find on AmazonWhat size generator to run a well pump (1 hp)?
Short answer
A well pump (1 hp) draws about 2,000 running watts but surges to roughly 3,000 starting watts when its motor kicks on, so you need a generator rated for at least 3,000 starting watts to run one on its own — a 3,000W unit gives comfortable headroom.
Running watts
2,000W
Starting watts
3,000W
Minimum generator
3,000W
Recommended
3,000W
Sizing a generator for a well pump (1 hp)
A well pump (1 hp) runs at about 2,000 watts, but its motor briefly pulls 3,000 starting watts — 1,000 extra — for a fraction of a second when it kicks on. That surge, not the running figure, sets the minimum generator size, which is why a generator sized only on running watts can stall the moment the motor starts.
To run one on its own, choose a generator rated for at least 3,000 starting watts. To run it alongside other essentials, add up everything you need and size up — the calculator below does that math for your exact list.
Run your full appliance list
This page covers the well pump (1 hp) on its own. Open the calculator with it pre-selected, then add everything else you plan to power at the same time.
Size a generator with a well pump (1 hp)Recommended recreational / portable generators
Real, widely available units in the Up to 3,500W class. Independent picks — we're not affiliated with any manufacturer or retailer and earn nothing from these links.
Best value
Westinghouse iGen2200
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Champion 2500W Dual Fuel Inverter (201183)
2,500W start · 1,850W run
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Find on AmazonFrequently asked questions
What size generator do I need to run a well pump (1 hp)?
To run a well pump (1 hp) on its own you need a generator rated for at least 3,000 starting watts. We recommend a 3,000W (recreational / portable) unit so you have headroom to add other appliances without running the generator at its limit.
How many watts does a well pump (1 hp) use?
A well pump (1 hp) uses about 2,000 running watts continuously, and briefly spikes to roughly 3,000 starting watts (1,000 extra) at the instant its motor kicks on. Always check your unit's nameplate for exact figures.
Why does a well pump (1 hp) need more starting watts than running watts?
Its motor needs a short burst of extra power — usually 2-3x its running wattage for a fraction of a second — to overcome inertia and get moving. That surge is what actually determines the generator size, which is why sizing on running watts alone leaves you short.