How Many Amps Does a Home Woodworking Shop Actually Need?

Most garages already have a 15 or 20-amp circuit, and most beginners never think about amperage until a breaker trips mid-cut. Understanding the numbers ahead of time is a five-minute check that prevents a genuinely dangerous habit: running high-draw tools off a shared extension cord.

What a standard circuit can carry

A 15-amp circuit at 120 volts safely carries about 1,440 watts of continuous load; a 20-amp circuit carries about 1,920 watts. In practice, electricians recommend staying under 80% of that rating for continuous use, which puts a realistic ceiling closer to 1,150–1,540 watts depending on the circuit.

What common tools actually draw

• Circular saw: roughly 1,200–1,800 watts under load.
• Shop vacuum: roughly 1,000–1,400 watts.
• Router: roughly 1,000–1,800 watts, depending on size.
• Contractor-style table saw: often 1,800–2,200 watts, close to or over a single 15-amp circuit's realistic ceiling on its own.

A circular saw and a shop vacuum running at the same time can already approach 2,600 watts combined — more than a single 15-amp circuit should carry continuously.

The habit that causes most tripped breakers (and fires)

Daisy-chaining power strips or running two high-draw tools off one extension cord is the most common cause of both a tripped breaker and, in worse cases, an overheated cord. Spreading tools across separate outlets on separate circuits — not just separate outlets on the same circuit — is what actually solves this.

When to consider a dedicated circuit

If a shop regularly runs a stationary saw, dust collection, and lighting at once, a dedicated 20-amp (or 240-volt for larger stationary tools) circuit run by a licensed electrician is worth the cost. It is a one-time expense that removes the guesswork permanently, rather than a workaround repeated every session.

Setting up the rest of the shop? See the workshop setup mistake that costs beginners the most.