How often to update a price list when copper moves (simulator with real data)

How often to update a price list depends on how much copper and the euro-dollar rate move between two updates compared with your margin. With real monthly data from August 2023 to July 2026, a list with 70% copper in its cost updated every month fell at most 6.6% behind cost; updated quarterly, 12.5%; every six months, 20%, more than a 15% margin. Pick the longest interval whose worst drift still leaves you a margin, and add a trigger to review early when the index jumps.

Replay the last three years with your margin

With the example figures (70% copper, 15% margin, bought in dollars), the worst month for the quarterly list was January 2026: cost was 12.5% above the cost the list was built on, and that month’s margin fell to 4.3%. With a monthly list, the worst month was April 2024 and the margin never went below 9.4%. With a six-monthly list, there was one month of selling below cost.

What data the simulator uses (and what it doesn’t)

• Copper: the International Monetary Fund series “Global price of Copper”, in US dollars per metric ton, published on FRED (Federal Reserve Bank of St. Louis). Its notes say the prices are period averages in nominal dollars. The latest value available on 11 October 2026 is July 2026.
• EUR/USD: the European Central Bank reference exchange rate, monthly average (series EXR.M.USD.EUR.SP00.A on the ECB Data Portal).
• It is not the LME price. These are monthly averages, not the London Metal Exchange daily settlement price. An average smooths out peaks: within a month, the real gap between cost and list can be larger than the simulator shows.
• Weekly or fortnightly cannot be measured with one value per month. Updating more often than monthly also trims moves within the month, but this data cannot say by how much.

The model is simple on purpose: the share of the cost tied to copper rises and falls with the copper price, the rest stays flat, and if you buy in dollars the whole cost is converted to euros at that month’s rate. Each new list is built on the last full month’s average, which is what you have when you publish it. It is the same formula as in the guide to the metal-indexed price list.

What moved in these three years

• Copper went from a monthly average of 7,941 USD/t in October 2023, the low in this window, to 13,552 USD/t in June 2026, the high (IMF via FRED).
• The largest month-on-month rise was in January 2026: from 11,791 to 12,987 USD/t, 10.1%. In April 2024 it rose 8.7%, from 8,693 to 9,446 USD/t.
• The euro went from an average of 1.0354 dollars in January 2025 to 1.1824 in February 2026 (ECB). Between January and June 2025 alone it went from 1.0354 to 1.1516, 11.2% higher: whatever you buy in dollars cost about 10% less in euros without the supplier changing anything.
• Sometimes the currency offsets copper and sometimes it pushes in the same direction. In April 2024 copper rose while the euro fell from 1.0872 to 1.0728, which is why it is the worst month for a monthly list bought in dollars.

How to choose the interval

The arithmetic behind it is short: if cost is X% above the cost you built the list on, you lose X × (1 − margin) points of margin. With a 15% margin, a 17.6% gap takes it to zero. So the question is not “how often do others update?” but “how far has my cost moved, in the worst case, in the time my list stays in force?”.

1. Put your copper share and margin in the simulator and look at the lowest-margin column for each interval.
2. Keep the longest interval whose lowest margin you can live with. Every new list means review work and a notice to your customers, so updating more than needed has a cost too.
3. Add an override: if the index or the exchange rate moves more than a set percentage from the list in force, review before the date. In January 2026 copper rose 10.1% in a single month; a fixed calendar would not have caught it.
4. Check the number again when your margin or product mix changes. With less margin, the same interval holds less.

Lead time and stock count too: if you sell from stock bought months ago, your real cost lags the index, which can work for you or against you. The landed cost is the right starting point for the list. There are more guides on pricing, rules and trade in the HeavyDeals guides.

How HeavyDeals does it

HeavyDeals, the commercial system for industrial distribution, calculates every catalogue price from the indices (LME copper and EUR/USD) and your margin, with each customer’s discount. When the indices change, the catalogue recalculates, the changed rows are marked and someone on your team reviews it before it is saved. Every price list PDF carries the quotes it was calculated with and their date, so your customer knows which copper price it was built on. See how it works.

Every figure and rule was checked against the sources above, on the date shown next to each; last review of this guide: 11 October 2026. The examples use illustrative figures, not today’s quotes. This is not legal or tax advice. Written with the help of AI and reviewed by the HeavyDeals team.