Copper Weight Guide
1. Why weight matters in copper buying
Most copper products are priced by mass, not length. Converting dimensions to kilograms helps compare quotes, plan transport, and validate supplier invoices. This calculator converts geometry into volume and multiplies by density, giving fast theoretical weights for planning and budgeting.
2. Forms covered by this calculator
The tool supports sheet or plate, round rod, rectangular busbar, hex bar, tube or pipe, wire, and coil strip. Each form uses the correct cross-sectional area and length relationship. For hollow tube, it subtracts the inner area from the outer area to avoid overestimating material.
3. Typical copper densities and grades
Pure copper density is commonly near 8,960 kg/m³, but it can vary slightly by grade and processing. The calculator includes presets such as C110 (ETP), C101 (oxygen-free), and C122 (deoxidized). You can also enter a custom density when working with alloyed copper or vendor-specific data.
4. Unit handling and practical conversions
Projects often mix units, like thickness in millimeters and length in feet. This calculator converts all inputs into meters internally, so results remain consistent. You can switch linear units for width and length, separate thickness units, and diameter units. The output includes both kilograms and pounds for quick reporting.
5. Wastage, kerf, and fabrication allowances
Cutting and trimming create losses, especially for plate nesting, coil slitting, and busbar punching. Add a wastage percentage to account for kerf, end cuts, or test coupons. The calculator applies the allowance to the total weight, which is useful for ordering extra stock and reducing work stoppages.
6. Cost estimation from price per kilogram
When you enter a rate per kilogram, the calculator estimates total material cost using the weight including wastage. This helps compare suppliers and evaluate “per meter” quotes on a common basis. You can keep currency flexible by entering the rate in your preferred unit of money per kilogram.
7. Reverse mode for required length
Sometimes the target is a weight limit, not a length. Reverse mode calculates the length needed for one piece to meet your target weight, using density and cross-sectional area. This is useful for wire reels, coil strip ordering, and bar stock cut planning when weight constraints affect shipping or handling.
8. Tolerances and checking real deliveries
Calculated values are theoretical. Actual delivered weight may differ due to dimensional tolerances, ovality in tube, temper effects, or alloy composition. For critical work, measure several samples and compare. Use the breakdown values (area, cross-section, volume) to spot input mistakes and confirm the correct product form.
FAQs
1) Which density should I choose?
Use the preset that matches your supplier’s grade. If your certificate lists density or alloy, choose “Custom density” and enter that value. Small density differences can matter on large orders.
2) Why does tube weight need OD and ID?
Tube is hollow, so material volume equals the outer cylinder minus the inner void. Using OD and wall thickness or OD and ID ensures you calculate only copper metal, not empty space.
3) Can I calculate length from a target weight?
Yes. Select “Find length from target weight,” enter target kilograms, and provide cross-sectional dimensions. The tool computes the required length for one piece using density and cross-sectional area.
4) How accurate are AWG wire calculations?
AWG diameters are based on a standard formula, so the computed diameter is consistent. Real wire may vary slightly by insulation and manufacturing tolerance. Use measured conductor diameter when precision is required.
5) What wastage percent should I use?
For simple straight cuts, 1–3% is common. For complex nesting, punching, or slitting, 3–10% may be more realistic. Use your shop’s historical scrap rate for best results.
6) Does the cost include taxes or shipping?
No. The cost feature multiplies weight (including wastage) by your entered price per kilogram. Add taxes, freight, and handling separately to match your procurement process.
7) Why can results differ from supplier invoices?
Suppliers may bill by measured mass, nominal sizes, or bundle weights. Tolerances and moisture or packaging can affect totals. Compare your inputs and use the breakdown values to validate geometry.