Normalize the measured dimensions
All lengths are stored in millimetres for compatibility with existing MaterialNest measurements and Planner handoffs. One international foot is exactly 304.8 mm. Decimal yards multiply by 914.4 mm; metres multiply by 1,000 mm. A US depth in inches divides by 12 to become feet. Feet-plus-inches input normalizes before multiplication.
NIST SP 811 Appendix B.9 supplies official area and volume conversions; NIST's revised foot factors distinguish the international foot from the obsolete US survey foot. MaterialNest uses 1 ft = 0.3048 m and 1 yd = 0.9144 m exactly.
Add volumes without intermediate rounding
For each rectangular section, volume ft³ = length_ft × width_ft × depth_ft. Sum section volumes before conversion. Cubic yards = total ft³ ÷ 27 because 1 yd = 3 ft, so 1 yd³ = 27 ft³. Cubic metres = yd³ × 0.764554857984 exactly as a conversion factor.
For the loadable fill record, convert the 6 in depth to 0.5 ft before multiplying: (12 × 9 + 6 × 3) × 0.5 = 63 ft³. Dividing once after summation gives 7/3 yd³; multiplying that unrounded value by 0.764554857984 gives 1.783961335296 m³. Adding separately rounded yard displays can instead alter the total. JavaScript floating-point arithmetic retains intermediate values; only display values round to four decimal places. Display rounding is not purchasing rounding, and very small positive quantities may display as zero. Canonical saved/handoff measurements retain the calculation precision.
Limits and next quantities
Version 1.0.0 supports up to 30 sections, positive finite dimensions up to 1,000,000 mm each and unique section names. Empty sections, zero dimensions, negative values and nonfinite numbers are rejected. Dimension-only sections rely on the user's non-overlapping sketch; no spatial placement is inferred.
No allowance or supplier order increment is included. Gravel adds an entered density estimate; Aggregate Ordering adds exact purchasing terms. Use the bulk measurement guide and volume/weight decision to keep geometry, material state and purchasing distinct.