Number Material Weight Calculator
One weight tool instead of a shelf of single-material ones: 18 materials with their densities printed, five shapes, and the answer in pounds, kilograms and tons — with the volume shown so you can check the math.
Densities are standard reference values for dry material at room temperature, printed next to each material so nothing hides. Lumber varies with moisture — green oak can run 20% heavier than the kiln-dried figure; bulk materials (gravel, sand, soil) vary with compaction and moisture, so treat bulk answers as ±10%.
How it works
Weight = volume × density, every time. The shapes only change the volume: plate = length × width × thickness; round bar = π × (diameter/2)² × length; tube = π × (outer radius² − inner radius²) × length, with the inner radius from your wall thickness; block/fill = length × width × depth; cylinder = π × (diameter/2)² × length. Results show cubic feet and cubic yards alongside pounds, kilograms and tons, because half the time the real question is a truck or a trailer, not a scale.
Formula & worked example
Formula: Weight = volume × density. Plate: L × W × (thickness ÷ 12). Round bar: π × (diameter ÷ 24)² × L (diameter in inches). Tube: π × ((OD/2)² − (OD/2 − wall)²) × length in inches ÷ 1,728. Block: L × W × (depth ÷ 12). Cylinder: π × (diameter in ft ÷ 2)² × length. Densities in lb/ft³, printed in the material list (steel 490, aluminum 169, concrete 150, oak 45, pine 31, gravel 105, water 62.4).
Worked example: A 4×2 ft steel plate at 0.5 in: volume 0.333 ft³ × 490 = 163.33 lb (74.1 kg).
When to use this
- You need to know if a trailer, truck bed or floor can carry a piece.
- A supplier quotes by weight and you are checking the figure.
- You are comparing materials — steel vs aluminum — for the same part.
- You are ordering bulk material sold by the ton but measured by volume.
How to use it, step by step
- Pick the material — its density in lb/ft³ is shown in the list.
- Pick the shape that matches the piece.
- Enter dimensions in the units each label asks for (plate thickness in inches, length in feet).
- For tube, enter the outside diameter as the diameter and set the wall thickness.
- Set quantity for multiples; read pounds, kilos and tons with the volume.
What the inputs mean
| Input | What it is | Typical values |
|---|---|---|
| Material density | Reference weight per cubic foot, dry — the multiplier for everything | Steel 490; aluminum 169; concrete 150; water 62.4 lb/ft³ |
| Shape | Which volume formula applies | Plate, round bar, tube, block/fill, cylinder |
| Thickness / diameter | In inches for plate, bar and tube; block depth also in inches | 0.5 in plate; 2 in tube OD |
| Wall thickness | Tube only: sets the inner diameter | 0.125–0.25 in common |
Another worked example
A gravel pad 10×8 ft at 4 in deep: volume 26.7 ft³ = 1.0 yd³, and at 105 lb/ft³ it weighs 2,800 lb — 1.40 tons. Order by the ton with a small overage; a "yard" from the landscape yard is this number, and your trailer’s rating decides how many trips it takes.
Frequently asked questions
How much does a 4×2 ft steel plate, 1/2 inch thick, weigh?
Volume = 4 × 2 × (0.5 ÷ 12) = 0.333 ft³. At steel’s 490 lb/ft³ that is 163.33 lb (74.1 kg). The same plate in aluminum (169 lb/ft³) weighs 56 lb — the density ratio is the whole story, which is why the density prints next to every material here.
How much does a yard of gravel weigh?
At 105 lb/ft³, one cubic yard (27 ft³) weighs about 2,835 lb — roughly 1.4 tons. The worked example here: a 10×8 ft pad at 4 in deep is 26.7 ft³ (1.0 yd³) and 2,800 lb. That is why gravel is sold by the ton and why a half-ton pickup makes two trips.
How much does steel tubing weigh?
A 2 in OD steel tube with a 0.25 in wall, 10 ft long: cross-section π × (1² − 0.75²) = 1.374 in², volume 0.0954 ft³, weight 46.77 lb. Wall thickness is the lever — the same tube at 0.125 in wall weighs about 26 lb. Always enter the real wall; nominal pipe sizes hide it.
Why does lumber weight vary so much?
Water. Kiln-dried pine at 31 lb/ft³ and green pine can differ by a third. The figures here are dry reference values; freshly pressure-treated or rain-soaked lumber runs heavier. For a trailer load of treated decking, add 20% margin to the dry answer.
What does a cubic foot of concrete weigh?
About 150 lb for normal-weight concrete — a cubic yard is just over 2 tons (4,050 lb). Lightweight mixes run 110–120 lb/ft³; if your mix is lightweight, pick the closest density or scale the concrete answer by 0.75.
Can I use this for water tank weight?
Yes — cylinder shape, water at 62.4 lb/ft³. A 24 in diameter, 4 ft long tank holds π × 1² × 4 = 12.6 ft³ ≈ 94 gallons and weighs about 784 lb full, before the tank itself. Floor and stand ratings care about exactly this number.
How accurate is this for bulk materials?
Within about ±10% for gravel, stone, sand and soil — moisture and compaction move bulk density more than the math does. It is the right precision for ordering and for load checks with margin, not for settling a weighbridge invoice.