Steel Weight & Cost Calculator — PRO

What this calculator does

• Catalogue mode — pick a standard section and get its mass directly from the selected standard:
  India ISMB/ISWB/ISHB/ISMC/ISA • US W, C, MC (AISC, converted from lb/ft → kg/m) • UK/EU UB, UC, PFC.
• Custom geometry mode — enter generic shapes (I‑beam, channel, angle, tee, flats, HSS square/rect/round) and a density to compute kg/m from area × density.
• Pricing — choose a built‑in 2025 price index for India/US/UK or enter a custom price per kg or per ton.
• Cut plan & waste — supply stock length and allowance. The tool computes stock bars/sections, waste (m) and waste (%).
• Batch CSV import & exports — sum multiple catalogue lines and export results/report.

Supported standards & series

How it works (math & logic)

Catalogue path

When you pick a catalogue designation, the tool takes its published mass per unit length M (kg/m) and uses it directly:

Unit weight (kg/m) = M (from standard)
Total weight (kg) = M × Length_per_piece (m) × Quantity
Total cost = Total weight × Price_per_kg

Custom geometry path

The widget computes cross‑sectional area in mm² from your inputs and multiplies by density:

kg/m = Area(mm²) × Density(kg/m³) / 1,000,000

Areas used (idealized without fillets):

Catalogue masses already include fillet effects defined by each standard. Custom geometry is a budgeting approximation.

Price logic

You can select a country index or provide your own rate. The calculator stores an internal Price_per_kg. When you select Price per ton, the custom input is divided by 1000 to convert to per‑kg internally; the KPI label changes to “Price per ton”.

Cut plan & waste

perBar = floor(Stock_length / Length_per_piece)
if perBar > 0:
  bars  = ceil(Quantity / perBar)
  used  = min(Quantity, bars·perBar) × Length_per_piece
  waste = bars·Stock_length − used
else:
  bars  = Quantity   (each piece takes a full stock member)
  waste = max(0, bars·Stock_length − Quantity·Length_per_piece)

waste_with_allowance = waste + (Quantity·Length_per_piece) × (Allowance%)
waste_percent        = waste_with_allowance / (bars·Stock_length)

When perBar = 0 (piece longer than stock), the waste % is shown as “N/A”.

Safety & validation

• Checks like 2t < height (I/Channel/Tee), 2t < OD (pipes), and t < legs (angles) prevent impossible sections.
• Length > 0 and Quantity ≥ 1 are enforced.

How to use (step‑by‑step)

1. Choose Mode: Catalogue for published sections, or Custom for generic shapes/rebar.
2. If Catalogue: pick Region → Series → Designation. If Custom: pick Shape and enter dimensions (mm) and Density.
3. Enter Length per piece (m) and Quantity.
4. Set Price: choose built‑in country index or pick Custom and enter a price per kg or per ton (with currency).
5. Set Stock length and Allowance (%) for cutting waste.
6. Click Calculate to see Unit kg/m, Total kg, Price per kg/ton, Total cost, Stock bars, Waste (m & %).
7. Use Generate HTML Report or Export CSV to save results. Use Batch Import (CSV) to add multiple catalogue lines.

Sample project — Mezzanine Beams (ISMB 200)

Let’s budget 12 beam pieces for a small mezzanine. We’ll use Indian catalogue data and a 2025 India price index.

Manual calculation (to verify the widget)

1. Total weight = 24.17 × 4.5 × 12 = 1305.18 kg
2. Total cost = 1305.18 × 40.58 = ₹ 52,964.20 (rounded)
3. Cut plan:
   • perBar = floor(12 / 4.5) = 2
   • bars = ceil(12 / 2) = 6
   • used = min(12, 6×2) × 4.5 = 54.0 m
   • waste = 6×12 − 54.0 = 18.0 m
   • allowance = 54.0 × 2% = 1.08 m
   • waste (with allowance) = 19.08 m
   • waste % = 19.08 / 72 × 100 = 26.50%

This example shows why choosing lengths compatible with stock (e.g., 6.0 m or 4.0 m increments) can drastically reduce waste.

Batch CSV format (catalogue lines)

Upload a .csv file with either five or four columns per line:

region,series,designation,length_m,qty
# or (region omitted → uses current region in the UI)
series,designation,length_m,qty

Example (mixed regions):

IN,ISMB,MB 200,4.5,12
US,W,W12x26,6,8
UK,UB,UB 305×165×40,5,6

The widget totals the kg and cost using your current price settings.

Jargon buster

• Series / Designation — The catalogue family and specific size (e.g., ISMB 200, W12×26, UB 305×165×40).
• kg/m — Mass per unit length. Catalogue values already include fillets; custom geometry is idealized.
• Density ρ — Material density (kg/m³). Mild steel ≈ 7850, stainless ≈ 8000.
• Price per kg / ton — Your rate basis. If you enter per‑ton, the tool divides by 1000 internally.
• Stock length — Standard supply length of a bar/section used to estimate cutting and waste.
• Allowance — Extra length loss: cutting, miscuts, corrosion allowance, etc., added as a percentage of total required length.
• HSS — Hollow Structural Section (square/rectangular/round).

Tips & limitations

• Catalogue masses come from their respective standards (IS 808 / AISC / UK Blue‑Book style tables). Custom geometry is best for early budgeting and non‑catalogue shapes.
• For tight design compliance (e.g., connection detailing, section properties), always refer to the full standard tables and manufacturer data.
• Consider optimizing lengths to match stock and reduce waste (e.g., nesting 2×6.0 m from a 12.0 m stock).