How to use this calculator
- Enter or choose dimensions in.
- Enter or choose inside length.
- Enter or choose inside width.
- Enter or choose inside height.
- Enter or choose board thickness.
- The inside volume updates as you type. Use Copy result or Share to keep it.
Method
Inside volume = L × W × H; Outside ≈ (L + 2t) × (W + 2t) × (H + 2t)
- L, W, H
- inside dimensions
- t
- board thickness
- 1 ft³
- 28.316846592 L (exact)
Worked example
- Inside = 400 × 300 × 250 = 30,000,000 mm³ = 30 L = 0.03 m³.
- 0.03 m³ ÷ 0.0283168 m³/ft³ = 1.0594 ft³.
- Outside ≈ 408 × 308 × 258 mm = 32.42 L.
A 400 × 300 × 250 mm box holds 30 litres (1.06 ft³) and takes up about 32.4 litres from the outside.
What the result means
Use inside volume to check product fit and fill; use the outside volume for pallet and container planning.
Assumptions and limits
- The box is a rectangular prism.
- The outside volume is approximate: RSC flaps overlap, so the real outside height can be a little more than inside height plus two thicknesses.
Questions
Is the outside volume used for courier charges?
Couriers measure the outside, so measure the real box or use the approximate outside size with the dimensional weight calculator.
How do I convert litres to cubic feet?
Divide litres by 28.3168.