Market Data

Plastic Resin Prices at 310.75: What Molders Should Actually Budget

Resin is the largest line in most molders' cost sheets and the one they control least. Here is the current price trend, the natural-gas feedstock link that drives it, and how to build a resin budget that survives contact with the market.

For an injection molder, resin is typically the single largest cost on the part, often more than half of total manufacturing cost, and it is the input over which the molder has the least direct control. The producer price index for plastic resins and materials, the cleanest published measure of that cost, reads 310.75 index (1982=100) as of Jun 2026, up about 17.2% from a year ago. Budgeting resin off last quarter's price is how molders discover margin compression at the worst possible moment: mid-contract, on a fixed-price job.

Resin is downstream of natural gas

Most commodity resins trace back through the petrochemical chain to natural gas liquids, which is why the resin index and the gas market move together with a lag. Industrial natural gas currently runs $4.27/Mcf (May 2026), down about 9.0% from a year ago, and a sustained move in gas tends to show up in resin contract prices a month or two later as producers adjust. That lag is a planning gift: watching the gas tape gives a molder advance warning of where resin is heading, enough time to time a buy, negotiate a contract window, or add an escalation clause before the increase arrives.

A molder who watches only the resin invoice is always reacting. A molder who watches the gas market is forecasting.

Building a budget that survives the market

A defensible resin budget does three things a static one does not. It prices at the current index, not a stale contract memory. It carries a sensitivity band, because a resin quoted flat for a year is a bet the market rarely honors, so the budget should show what a 10% move does to the part. And it pairs any fixed-price customer quote longer than a quarter with an escalation clause tied to a published index, so a feedstock spike does not come out of the molder's margin. The index charted above is the natural reference for that clause: neutral, public, and updated monthly.

Six years of the resin budget

Over the 36-year record resin prices have moved decisively rather than oscillated: from 132.10 at the close of 1990 to 310.75 today, up 135%, and now in the upper third of its 36-year range. A change of that size across a span this long is a level shift, not a cycle, and planning that assumes a return to the 1990 figure is planning against the whole record.

Use the chemical cost per pound calculator to translate the current resin index into your part's material cost. Price the resin line

Published 2026-08-05.