the title says all
Most of them are 1/4 horsepower. More expensive models may be as much as 1/3 horsepower.
+1 That's what I thought as well.
In the UK, they're nearer 2hp.STeve
Another way to approach the electrical HP capacity. Contemporary USAC 117 VAC outlets should be fused for 15 Amps. The leaf Craftsman blower in my shop is rated 120VAC AT 6.5 Amps. Which is 780 Watts or 1.05 HP. I believe my leaf blower is average so this answers One Horsepower. A