Will your amp really drive your speakers? A few watts can fill a room on efficient horns, yet run out of breath on small bookshelf speakers. This calculator shows where your setup lands in about a minute.

• Your gear: pick your amp and speakers from the menus, or type in the numbers from their spec sheets.
• Your room: enter the room size, then drag the seat to where you sit.
• Your listening: set how loud you usually play and the kind of music you love.

Now look at the bar at the top. It shows your headroom, the power held in reserve for sudden loud moments like a drum hit or a full orchestra coming in.

• Green means you’re in good shape. The amp has power to spare, so loud moments come through clean.
• Amber means just enough. You’re fine most of the time, but the biggest peaks will touch the limit.
• Orange means the amp is short on power. Loud passages will clip, so try a stronger amp, more sensitive speakers or a lower volume.

Thinking about an upgrade? The color grid at the bottom, called the match map, shows how other amps and speakers would do in your room. Tap any square to try that combination.