Metal Order Quantity Calculator
Calculate the raw metal stock required to produce a required number of finished pieces, including material waste, production yield and optional safety stock.
Order quantity results
Finished pieces required
—
Base material requirement
—
Expected production waste
—
Expected finished yield
—
Formula
Base material =
finished pieces × material per finished piece
Material required after yield =
base material ÷ (yield ÷ 100)
Safety stock =
yield-adjusted material × safety allowance ÷ 100
Recommended raw stock =
yield-adjusted material + safety stock
Expected waste =
recommended raw stock − base material
A yield percentage is mathematically different from simply adding the same percentage as waste. For example, 90% yield means dividing the required finished material by 0.90.
Example
Order
100 finished pieces requiring 2.5 kg of material each.
Base requirement
100 × 2.5 kg = 250 kg.
90% production yield
250 ÷ 0.90 = 277.78 kg required before safety stock.
5% safety allowance
277.78 × 5% = 13.89 kg additional stock.
Recommended order
Approximately 291.67 kg of raw material.
Why raw material requirements increase
- Machining removes material as chips.
- Cutting creates kerf and end losses.
- Sheet and plate processing creates nesting waste.
- Forging, forming and fabrication can create trim waste.
- Some parts may fail inspection and require replacement.
- Setup and trial pieces consume material.
- Material handling can create damage or unusable remnants.
- Safety stock protects against unexpected production losses.
Actual production yield depends on the manufacturing process, part geometry, nesting efficiency, cutting method, machining allowance and defect rate. Use historical production data when available.
Frequently Asked Questions
How much raw metal do I need for an order?
Enter the finished quantity, material required per piece and expected production yield. The calculator estimates the raw stock requirement.
What is production yield?
Production yield is the percentage of raw input that becomes usable finished product.
Why does 90% yield require dividing by 0.90?
Because only 90% of the input becomes usable output. Dividing the required output by 0.90 determines the required input.
Can I add safety stock?
Yes. Enter an additional percentage to account for uncertainty or extra production requirements.
Can I calculate raw stock pieces?
Yes. Enter the usable material available from one standard stock piece and the calculator rounds the required order quantity upward.
Does the calculator calculate waste?
Yes. It shows the estimated difference between recommended raw stock and the theoretical material required in the finished pieces.
Can this be used for metal sheets, bars and plates?
Yes. The core calculation applies to any raw metal stock when the material requirement per finished piece is known.