Dad’s short answer: The box number is measured on the lowest setting with a non-powered tool attached — not how anyone vacuums. With a powered floor head on a normal setting expect a good deal less, and on boost expect roughly ten to fifteen minutes.

How the advertised number is measured

Manufacturers quote eco mode with a plain tool on the end, because a motorized brush head draws its own power on top of the suction motor. Attach the floor head and you're pulling from two motors, and the runtime drops.

Then there's boost, which is what you need on carpet and what drains a battery fastest. A machine advertising sixty minutes will often give you the low teens on boost with the powered head running.

None of that is a scandal, it's just how the spec is written. But it means you should size the machine to your home using the realistic number, not the headline.

Sizing it to your house

Time yourself vacuuming with whatever you own now. That's the number to beat, and most people are surprised how long it actually takes.

If your house needs more than about twenty minutes of powered-head time, look for a machine with a removable battery and buy a second one. Swapping takes a second; waiting hours for a recharge does not.

If the battery is built in and not removable, know that before you buy — both for runtime and because a sealed battery means the machine's lifespan is the battery's lifespan.

Auto surface detection helps here too. A machine that only ramps to full power when it hits carpet stretches a charge meaningfully further than one you leave on boost the whole time.

Dad’s Take: Take the box number, imagine a third of it, and size your house against that. You'll be about right.