CFT Calculator (Cubic Feet)
Use this calculator to quickly find volume in cubic feet (CFT) for rectangular spaces or cylinders. Great for concrete, sand, soil, wood, and storage estimates.
What Is CFT?
CFT means cubic feet, a unit used to measure volume. If square feet tells you area (2D), cubic feet tells you space (3D). It is commonly used in construction, interior work, transportation, warehousing, and material estimation.
For example, when someone asks how much sand, concrete, gravel, or storage space you need, CFT is often the unit that gives a practical answer.
How to Calculate CFT
1) Rectangular Formula
For a box-shaped space or slab:
CFT = Length × Width × Height
All dimensions must be in the same unit first. If your measurements are in inches or meters, convert them before calculating, or let this calculator handle conversion automatically.
2) Cylindrical Formula
For columns, pipes, tanks, or round holes:
CFT = π × (Diameter ÷ 2)² × Height
This is especially useful when estimating concrete for round pillars or volume inside cylindrical containers.
3) Add Quantity and Waste
- Quantity multiplies volume for repeated units (like multiple identical pits or boxes).
- Waste % adds extra material for spill, cuts, compaction, or practical margin.
Worked Examples
Example A: Room Volume
A room measures 12 ft × 10 ft × 9 ft.
Volume = 12 × 10 × 9 = 1080 CFT
Example B: Concrete Slab (in inches)
Slab dimensions are 120 in × 96 in × 6 in.
- Convert to feet: 10 ft × 8 ft × 0.5 ft
- Volume = 10 × 8 × 0.5 = 40 CFT
Example C: Cylindrical Pit
Diameter = 4 ft, depth = 6 ft.
- Radius = 2 ft
- Volume = π × 2² × 6 ≈ 75.40 CFT
Why This Matters in Real Projects
- Construction planning: Estimate concrete, sand, brick fill, and earthwork.
- Logistics: Check shipment and container capacity.
- Storage: Understand warehouse or tank volume.
- Budgeting: Convert volume to material quantity and cost.
Quick Conversion Reference
- 1 cubic yard = 27 CFT
- 1 cubic meter = 35.3147 CFT
- 1 CFT = 28.3168 liters
- 1 foot = 12 inches
Common Mistakes to Avoid
- Mixing units (e.g., feet with inches in the same formula).
- Using area formula by mistake instead of volume formula.
- Ignoring waste factor for practical site conditions.
- Rounding too early in multi-step calculations.
FAQ
Is CFT the same as square feet?
No. Square feet measures area, while CFT measures volume.
Can I use this for sand and gravel estimates?
Yes. Calculate volume in CFT first, then convert to weight if needed using material density.
Should I always add waste percentage?
In most real projects, yes. Even 5% to 10% can prevent shortages due to compaction, spillage, and handling loss.
Final Note
A reliable CFT calculation saves time, reduces material shortages, and improves cost planning. Use the calculator above for quick estimates, then verify with site-specific standards before final procurement.