How do you calculate plastic regrind savings?

Multiply annual regrind volume by the per-kg savings (virgin price minus regrind cost), then multiply by a quality factor. For 15,000 kg/year at $1.20/kg saved and a 0.95 factor, the gross-before-factor figure is $18,000 and the adjusted savings is $17,100/year.

What is the quality adjustment factor for?

It derates raw savings to account for parts you cannot make from regrind, slightly higher scrap on regrind blends, or color and property limitations. A 0.95 factor means you realistically capture 95% of the theoretical saving.

How do I calculate granulator ROI from regrind savings?

Divide the granulator's installed cost by the annual net savings (this savings figure minus energy, labor, and maintenance). At $17,100/year of gross savings, a granulator costing roughly $25,000 pays back in well under two years before operating costs.

How much can I really save with regrind?

It scales with volume and the virgin-regrind price gap. The example's $17,100/year comes from 15,000 kg at a $1.20/kg spread. Higher-priced engineering resins widen the gap and the savings per kilogram.

Does the savings number include the cost of running the granulator?

No. This is gross savings on material only. To get net benefit, subtract granulator electricity, operator labor, blade maintenance, and amortized capital — then compare against the gross figure for true payback.

Why use virgin minus regrind cost rather than the full virgin price?

Regrind is not free — it carries granulation energy, labor, and handling cost per kilogram. The true saving is the gap between buying virgin and producing usable regrind, which is why the formula uses the difference, not the full virgin price.

Injection Molding calculator

Plastic Regrind Savings Calculator

Plastic regrind savings estimates the annual dollars a molding operation keeps by reusing reground scrap instead of buying virgin resin, based on regrind volume, the price gap between virgin and regrind, and a quality derating factor. Plant managers and continuous-improvement engineers use it to justify granulator purchases, size in-house recycling programs, and prove the payback on closed-loop material handling. With resin often the dominant variable cost, regrind savings can fund equipment in a single year. This calculator turns a vague material-recovery habit into a defensible ROI number.

What this calculator does

Estimate annual material cost savings from using regrind instead of 100% virgin resin in injection molding production.
Use this when building a business case for a granulator purchase, evaluating cold runner vs. hot runner economics, or reporting material cost reductions to management.
It computes annual savings as regrind volume multiplied by the per-kg cost difference, then derated by a quality/yield factor.

Formula used

Annual savings = Regrind consumption x Cost savings per kg x Quality factor
Compare to granulator cost and maintenance for ROI calculation

Inputs explained

Annual regrind used in production:
Savings per kg (virgin price minus regrind cost):
Quality/yield derating factor:

How to use the result

Use it to build the business case for a granulator or recycling program, or to quantify savings already captured by an existing regrind loop.
It is a gross savings figure that ignores granulator capital, energy, labor, and maintenance — net ROI requires subtracting those operating costs.

Current U.S. benchmarks

The producer price index for plastic resins and materials stands at 319.371 (BLS, May 2026), up 19.5% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The U.S. has 9,635 plastics product manufacturing establishments employing about 677,302 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate plastic regrind savings? Multiply annual regrind volume by the per-kg savings (virgin price minus regrind cost), then multiply by a quality factor. For 15,000 kg/year at $1.20/kg saved and a 0.95 factor, the gross-before-factor figure is $18,000 and the adjusted savings is $17,100/year.
What is the quality adjustment factor for? It derates raw savings to account for parts you cannot make from regrind, slightly higher scrap on regrind blends, or color and property limitations. A 0.95 factor means you realistically capture 95% of the theoretical saving.
How do I calculate granulator ROI from regrind savings? Divide the granulator's installed cost by the annual net savings (this savings figure minus energy, labor, and maintenance). At $17,100/year of gross savings, a granulator costing roughly $25,000 pays back in well under two years before operating costs.
How much can I really save with regrind? It scales with volume and the virgin-regrind price gap. The example's $17,100/year comes from 15,000 kg at a $1.20/kg spread. Higher-priced engineering resins widen the gap and the savings per kilogram.
Does the savings number include the cost of running the granulator? No. This is gross savings on material only. To get net benefit, subtract granulator electricity, operator labor, blade maintenance, and amortized capital — then compare against the gross figure for true payback.

Last reviewed 2026-05-12.