Convert the copper price to kg and tonnes

Do it with the API

Request copper in USD, then convert the returned price to the weight unit you need. The endpoint is GET /v1/commodities/spot/XCU/USD. Its response includes price and unit: "pound"; the calculation starts with that per-pound price. Copper is a futures-based reference price and is available in USD only.

The multiplication follows the weight: a kilogram contains more pounds, so its price contains that many per-pound amounts. For tonnes, use the pounds in a metric tonne. Use the same returned price for both calculations so each result starts from the same quote.

1. Get your API key Create a free key for your Narwhal API account. Use it to authenticate the copper request; the same API key works with REST and MCP.
2. Set the environment variable Keep the key in an environment variable named NARWHAL_API_KEY. The Python request reads that variable and sends the key in the Authorization header as Bearer YOUR_KEY.
3. Request and convert the price Run the Python code to request the copper price from https://api.narwhalapi.com. It reads price as a number, multiplies it by the pounds in a kilogram, and multiplies the kilogram result by 1,000 for a metric tonne.
   Python, copper per kilogram and per tonne

   import os
   import requests
   
   r = requests.get("https://api.narwhalapi.com/v1/commodities/spot/XCU/USD",
                    headers={"Authorization": f"Bearer {os.environ['NARWHAL_API_KEY']}"}, timeout=10).json()
   per_lb = float(r["price"])               # the API quotes copper per pound (unit == "pound")
   LB_PER_KG = 2.2046226218
   print(f"{per_lb:.4f} per lb  {per_lb * LB_PER_KG:.2f} per kg  {per_lb * LB_PER_KG * 1000:,.0f} per tonne")

4. Read the output by unit Read the output in order: the price per pound, per kilogram and per tonne. Each amount is in USD. The output formats the pound price with four decimal places, the kilogram price with two, and the tonne price as a whole number.

Do it in a sheet or without code

Use the commodity converter for a one-off conversion. If your costing sheet already has a pulled copper price in USD per pound, put that price in B1 and use a formula for the weight unit your sheet needs. Keep the input cell labelled USD per pound so the input and the converted amounts are easy to distinguish.

=B1*2.2046226218

=B1*2204.6226218

Both formulas use the same per-pound input. The kilogram formula multiplies by the pounds in one kilogram; the tonne formula multiplies by the pounds in one metric tonne. Choose the tonne formula directly when the costing sheet is in tonnes. You can also multiply the kilogram result by 1,000, since a metric tonne contains 1,000 kilograms.

Keep the full conversion factor in the formula and round the displayed amount as needed for the example's format. The pound price is the input, so replacing it changes both converted prices. Label the result as USD per kilogram or USD per metric tonne; converting the weight unit leaves the currency as USD.

Which option to use when

Is a tonne the same as a short ton?

No. A metric tonne is 1,000 kg, or 2,204.62 lb, while a US short ton is 2,000 lb. The tonne formula here uses the metric definition, with the full factor of 2,204.6226218 pounds per tonne.

If a costing sheet says only ton, establish which weight unit it means before applying the formula. A result labelled per tonne here means per metric tonne. Using the metric factor for a quantity expressed in US short tons would mix two different weight units, so keep the unit name alongside the price in your sheet.

Why does a tonne price look different from other sources?

Different benchmarks and contract months can move apart. This calculation converts the spot reference price in USD per pound to a metric-tonne price. A weight conversion preserves the reference price's basis.

For a different copper grade or an LME-style quote, compare the unit and basis before comparing the amounts. Expressing two quotes per metric tonne does not make their benchmarks or contract months the same. If the quote you need has a different basis, multiplying this price by the tonne factor still gives a conversion of this reference price.

What unit should I look for in the response?

The unit field must read "pound" for these formulas. Both conversion factors assume that the response's price is a price per pound, so read the unit together with the amount.

A number alone does not identify its weight unit. Before using an amount in B1 or in the Python calculation, confirm that it represents USD per pound. Applying the same factors to a price already expressed per kilogram or per tonne would convert from the wrong starting unit.

Worked example: convert copper to kilograms and tonnes

On 24 October 2026, copper was $6.4676 per pound. Start with that price and multiply by 2.2046226218 to get the kilogram amount. For the metric-tonne amount, multiply the same per-pound input by 2,204.6226218.

For the kilogram calculation on 24 October 2026, the result is approximately 14.2586, displayed as $14.26 per kilogram. Use the full factor, 2.2046226218 pounds per kilogram, in the multiplication. The shorter description of 2.2046 pounds per kilogram leaves out some of that factor’s decimal places.

Then calculate the metric-tonne price from the original per-pound amount. For the 24 October 2026 example, that gives approximately 14,258.6, displayed as $14,259 per tonne. If you calculate through kilograms instead, multiply the unrounded kilogram result by 1,000 before rounding the tonne display.