Coil ID / OD Calculator卷料內外徑計算
Calculations run in your browser and nothing you enter is collected.
Enter any three of ID, OD, width and weight, and the fourth is calculated automatically.
Formulas
- Coil weight
- Weight (kg) = π ÷ 4 × (OD² − ID²) × width × density ÷ 1,000,000, with all lengths in mm.
- Coil OD and ID
- OD = √(ID² + 4 × weight × 1,000,000 ÷ (π × width × density)); ID = √(OD² − 4 × weight × 1,000,000 ÷ (π × width × density)).
- Coil width
- Width = weight × 1,000,000 ÷ (π ÷ 4 × (OD² − ID²) × density).
FAQ
How do I find the coil OD from its weight?
With the ID, width, weight and density known, OD is the square root of (ID² + 4 × weight × 1,000,000 ÷ (π × width × density)). On this page, enter ID, width and weight and the OD is calculated automatically. Any three of ID, OD, width and weight give you the fourth.
Which density should I use?
Choosing a material fills in its reference density automatically. If you do not know the grade, choose "Aluminum, Copper or Iron / steel (grade not specified)" for a general estimate; if your material is not listed, choose Custom density and enter a value in g/cm³. Results are theoretical; actual weight is confirmed at shipment.
Need a quotation?
Contact Sursun Metals for assistance. Please tell us the material grade, thickness, width, coil weight or length, and quantity.