What a home workshop actually needs
Equipment tier matters more than any other input
A serious hobbyist workshop run regularly needs about 0.8 kW, around 2 panels. A heavy, professional-grade workshop run frequently with a dust collector needs closer to 2.4 kW, around 6 panels, a real jump driven mostly by tool wattage and how often they actually run.
Why actual run time matters more than owning the equipment
Power tools draw serious wattage only while actively cutting, sanding, or running, not just while sitting powered on in the shop. A table saw rated around 2,800 watts, toward the higher end of the 1,500 to 3,000 watt range most household and workshop table saw models fall into, used for 3 hours a week uses far less energy over a year than the same saw run 15 hours a week, which is why this tool asks for actual run time rather than assuming a fixed schedule from the equipment tier alone. The Department of Energy's homeowner's guide to solar covers sizing for homes with heavy workshop loads.
Dust collectors run alongside the main tool, not on their own schedule
A dust collector adds roughly 400 kWh a year in this estimate, since it typically runs whenever the main cutting or sanding tool is running rather than on a separate schedule of its own. Collectors are commonly wired on their own dedicated circuit specifically because they operate simultaneously with whichever stationary machine is active, a wiring practice the National Electrical Code (NFPA 70) addresses for workshop circuits. This tool adds that as a flat addon on top of the equipment tier rather than folding it into the base wattage.
How this differs from sizing a whole detached garage
This tool sizes just the workshop equipment load, based on tool tier and run time. The detached garage tool sizes an entire standalone structure, including lighting, doors, and the option of EV charging, a broader question than tool wattage alone.
What to do with this number next
Once you know your target system size, check the federal ITC calculator for programs that might apply, and use the roof space estimator to confirm the workshop roof itself has enough usable area. Workshop tools with motors also draw a surge at startup, so the inverter needs to handle that peak, a difference the inverter continuous vs peak rating calculator walks through.