GeneratorWatts

What size generator to run a air compressor (1.5 hp)?

Short answer

A air compressor (1.5 hp) draws about 1,500 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

1,500W

Starting watts

3,000W

Minimum generator

3,000W

Recommended

3,000W

Sizing a generator for a air compressor (1.5 hp)

A air compressor (1.5 hp) runs at about 1,500 watts, but its motor briefly pulls 3,000 starting watts 1,500 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 air compressor (1.5 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 air compressor (1.5 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 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.

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Best value

Westinghouse iGen2200

2,200W start · 1,800W run

Gasoline · Inverter · 52 dBA · excellent fuel economy

Matches the Honda’s 1,800W running output for a fraction of the price, and sips even less fuel.

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Budget pick

Champion 2500W Dual Fuel Inverter (201183)

2,500W start · 1,850W run

Dual fuel (gas / propane) · Inverter · CO Shield auto-shutoff · ultralight

Runs on gasoline or propane and includes a built-in carbon monoxide shutoff sensor.

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Frequently asked questions

What size generator do I need to run a air compressor (1.5 hp)?

To run a air compressor (1.5 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 air compressor (1.5 hp) use?

A air compressor (1.5 hp) uses about 1,500 running watts continuously, and briefly spikes to roughly 3,000 starting watts (1,500 extra) at the instant its motor kicks on. Always check your unit's nameplate for exact figures.

Why does a air compressor (1.5 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.