Net Volume Helper

"Box volume" in the sealed-box and port calculators means net internal airspace — not the outside dimensions of the box you're cutting. This tool walks through the real conversion: external dimensions minus wall thickness, minus whatever space your driver(s), port, and bracing take up inside — sourced from this site's enclosure-design research notes, not invented here.

External box dimensions

Defaults to 0.75in — standard 3/4" MDF, the baseline material per the enclosure knowledge base.

Driver displacement

The 8/10/12/15" values are fallback estimates from cross-referenced sources — always prefer your driver's actual published displacement if you have it. No 18" preset: two real published 18" drivers found during review disagreed by over 60% (0.24 vs 0.39 ft³) — too wide a spread for a responsible single fallback. Use Custom for 18" and larger drivers.

Port displacement (optional)

Don't know your port length yet? Leave this on "no port yet," get your net volume, then run the Port Calculator — its result will be close enough that re-checking port displacement afterward rarely changes the tuning meaningfully.

Bracing displacement (optional)

Only matters for large brace panels, not thin dowel bracing. Estimate one brace as (length × width × thickness, in inches) ÷ 1728, and sum if you have more than one. Leave at 0 if bracing is minimal.
Fill in the external dimensions and driver info, then hit Calculate.