Box Volume from Dimensions

Rectangular:

V_gross = L × W × H
V_net = V_gross − V_driver − V_port − V_bracing

Rule of thumb for deductions: - 10" woofer: 0.1 ft³ displacement - 12" woofer: 0.15 ft³ - 15" woofer: 0.25 ft³ - 18" woofer: 0.35 ft³ - 4" round port × 12" long: 0.06 ft³

Unit conversion:

1 ft³ = 1728 in³ = 28.317 L
1 L = 61.02 in³ = 0.0353 ft³