Formula
Cubic yards = length ft × width ft × (depth inches ÷ 12) ÷ 27. Planning cubic yards = cubic yards × (1 + allowance percent ÷ 100).
Trade & Construction
Calculate cubic yards from length, width and depth in feet and inches, with measured cubic feet, cubic metres, ordering allowance, rounded order quantity and a printable concrete, gravel, soil, mulch or classroom job note.
Trade & Construction
Cubic yards = length ft × width ft × (depth inches ÷ 12) ÷ 27. Planning cubic yards = cubic yards × (1 + allowance percent ÷ 100).
This is the method behind the answer, so the result can be checked rather than simply trusted.What-if check
Same measured hole, bed or slab footprint with different extra quantities. Keep the exact measured volume separate from the ordering buffer.
| Allowance | Order volume | Note |
|---|---|---|
| 0% | 1.4815 yd³ | Measured only |
| 5% | 1.5556 yd³ | Planning buffer |
| 10% | 1.6296 yd³ | Current setting |
| 15% | 1.7037 yd³ | Planning buffer |
Visual proof
40 cubic feet ÷ 27 = 1.4815 measured yd³. Current planning quantity: 1.6296 yd³.
Visual grid
Length, area, volume and material estimates are grid problems too: measure the space, account for edges and allowances, then turn the pattern into a number you can use.
Space calculations turn a real surface, room, run or volume into cells, edges and allowances that can be quoted, ordered or checked.
CalculationTime
Cubic yards = length ft × width ft × (depth inches ÷ 12) ÷ 27. Planning cubic yards = cubic yards × (1 + allowance percent ÷ 100).
Use this space on the printed report for client, supplier, classroom, job-location, measurement, quote or approval notes.
Cubic yards = length ft × width ft × (depth inches ÷ 12) ÷ 27. Planning cubic yards = cubic yards × (1 + allowance percent ÷ 100).
For 12 ft × 10 ft × 4 in: depth in feet = 4 ÷ 12 = 0.3333 ft. Cubic feet = 12 × 10 × 0.3333 = 40 ft³. Cubic yards = 40 ÷ 27 = 1.4815 yd³. With 10% allowance, planning quantity = 1.4815 × 1.10 = 1.6296 yd³.
Master’s Tip: measure the depth in several spots and write the allowance reason on the report. A neat cubic-yard number is less useful than a record that says whether extra quantity covers compaction, uneven grade, forms, spillage or supplier rounding.
Standard or basis: US customary volume relationship, where 1 yard = 3 feet and therefore 1 cubic yard = 27 cubic feet. The page uses arithmetic only and does not approve structural concrete, soil compaction, drainage or code requirements.
Methodology & Accuracy
CalculationTime pages are built around visible arithmetic: the formula, assumptions, worked example and practical limitations are shown so the result can be checked rather than simply trusted.
Cubic yards = length ft × width ft × (depth inches ÷ 12) ÷ 27. Planning cubic yards = cubic yards × (1 + allowance percent ÷ 100).
Standard or basis: US customary volume relationship, where 1 yard = 3 feet and therefore 1 cubic yard = 27 cubic feet. The page uses arithmetic only and does not approve structural concrete, soil compaction, drainage or code requirements.
Where a calculator follows a named legal, trade or industry standard, that standard is cited visibly. Otherwise the page uses transparent general arithmetic and states its limits.Master’s Tip: measure the depth in several spots and write the allowance reason on the report. A neat cubic-yard number is less useful than a record that says whether extra quantity covers compaction, uneven grade, forms, spillage or supplier rounding.
Multiply length in feet by width in feet by depth in feet to get cubic feet, then divide by 27 because one cubic yard contains 27 cubic feet.
Convert inches to feet first by dividing by 12. A 4-inch depth is 4 ÷ 12 = 0.3333 feet.
Often yes, but keep it separate from the exact measured volume. Extra quantity may cover compaction, uneven ground, waste, spillage or supplier rounding.
It uses the same rectangular-volume arithmetic, but concrete jobs may also need mix design, reinforcement, forms, delivery minimums and structural approval.
Yes for first-pass rectangular volume in cubic yards. For weight, bags or truck loads, check material density, compaction and supplier units separately.
Cubic yards are common in North American construction and landscaping because bulk materials are often sold by volume. A cubic-yard calculator turns tape-measure dimensions into a quantity that can be checked on a quote, delivery ticket or classroom worksheet.
A yard is three feet long, so a cube one yard on each side is 3 ft × 3 ft × 3 ft, or 27 cubic feet. That fixed relationship is the reason rectangular job measurements in feet can be divided by 27 to get cubic yards.
Lengths and widths are commonly measured in feet, while slab, gravel and mulch depths are often given in inches. Converting depth to feet before multiplying prevents a 12-times error.
For ordering material, the useful record includes measured length, width, depth, exact volume, allowance percent, formula, date/page context and a notes area for supplier rounding or site conditions.