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Plastic Part Cost Calculator

Estimate the material cost of an injection-moulded plastic part using its CAD volume, polymer density, resin price, production quantity and process allowances. The Plastic Part Cost Calculator helps engineers, students, researchers and product-development teams translate part geometry into estimated material usage and cost.

Calculator Inputs

cm³

The runner is the channel of solidified plastic that connects the mould gate to the part cavity. It is ejected with the part but is not the finished product. Enter its volume here to include runner material in the total shot weight and cost. Leave blank if you are using a hot-runner mould (no cold runner waste) or if the runner volume is not yet known.

g/cm³

Use your commercial grade's datasheet value for best accuracy.

parts
%

An additional percentage for process losses, start-up scrap and other consumption above the total shot weight. Default is zero.

S$/kg
S$/kg

Enter a future price to calculate cost exposure if resin prices change.

Enter your inputs and click Calculate to see results.

This calculator provides preliminary material estimates based on user-supplied inputs and representative density data. It is not a quotation or material specification. Actual consumption and cost may vary because of the selected commercial grade, additives, fillers, runner system, start-up losses, rejects, regrind policy and production conditions. Confirm material properties using the manufacturer's current technical datasheet.

Material cost is only one component of the finished-part cost. This estimate excludes tooling, machine time, labour, energy, inspection, secondary operations, packaging, overhead and commercial margin.

Compare all materials: mechanical, thermal & chemical properties

Plastics Density Reference

Only values with a valid source, completed technical review, and documented grade basis are shown. Density values are representative midpoints for unfilled injection moulding grades unless noted.

Acrylonitrile Butadiene Styrene

ABS

1.020–1.060 g/cm³

1040 kg/m³

General purpose injection moulding grade, unfilled

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.426; Harper (2006) p.2.3

Reviewed: 2026-07-01

Polyamide 6 (Nylon 6)

PA6

1.120–1.140 g/cm³

1130 kg/m³

Unfilled injection moulding grade, dry-as-moulded

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.478; Harper (2006) p.3.30

Reviewed: 2026-07-01

Note: Dry-as-moulded. Density decreases slightly with moisture absorption.

Polyamide 6,6 (Nylon 6,6)

PA66

1.130–1.150 g/cm³

1140 kg/m³

Unfilled injection moulding grade, dry-as-moulded

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.478; Matweb PA66 data (2026-07)

Reviewed: 2026-07-01

Note: Dry-as-moulded.

Polybutylene Terephthalate

PBT

1.300–1.320 g/cm³

1310 kg/m³

Injection moulding grade, unfilled

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.715; Matweb PBT data (2026-07)

Reviewed: 2026-07-01

Polycarbonate

PC

1.190–1.220 g/cm³

1200 kg/m³

General purpose injection moulding grade, unfilled

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.567; Harper (2006) p.3.39

Reviewed: 2026-07-01

Polyether Ether Ketone

PEEK

1.300–1.320 g/cm³

1310 kg/m³

Unfilled injection moulding grade

Test: ISO 1183-1 / ASTM D792

Source: Victrex PEEK datasheet (2026-07); Brydson (1999) p.600

Reviewed: 2026-07-01

Polyetherimide (Ultem)

PEI

1.270–1.290 g/cm³

1270 kg/m³

Unfilled injection moulding grade

Test: ISO 1183-1 / ASTM D792

Source: SABIC Ultem 1010 datasheet (2026-07); Harper (2006) p.3.52

Reviewed: 2026-07-01

Polyethylene — High Density

HDPE

0.941–0.965 g/cm³

955 kg/m³

Injection moulding grade, unfilled

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.208; Matweb HDPE data (2026-07)

Reviewed: 2026-07-01

Polyethylene — Low Density

LDPE

0.910–0.940 g/cm³

920 kg/m³

Injection moulding grade, unfilled

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.208; Harper (2006) p.3.5

Reviewed: 2026-07-01

Polyethylene Terephthalate

PET

1.330–1.360 g/cm³

1350 kg/m³

Injection moulding grade, unfilled, amorphous

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.715; Harper (2006) p.3.55

Reviewed: 2026-07-01

Note: Amorphous grade. Crystalline PET is denser (~1.38–1.40 g/cm³).

Polymethyl Methacrylate (Acrylic)

PMMA

1.170–1.200 g/cm³

1190 kg/m³

Injection moulding grade, unfilled

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.399; Harper (2006) p.3.43

Reviewed: 2026-07-01

Polyoxymethylene — Copolymer (Acetal)

POM-C

1.390–1.410 g/cm³

1410 kg/m³

Injection moulding grade, unfilled

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.535; Matweb POM-C data (2026-07)

Reviewed: 2026-07-01

Polyoxymethylene — Homopolymer (Acetal)

POM-H

1.410–1.430 g/cm³

1420 kg/m³

Injection moulding grade, unfilled

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.535; Harper (2006) p.3.46

Reviewed: 2026-07-01

Polyphenylene Sulphide

PPS

1.340–1.360 g/cm³

1350 kg/m³

Unfilled injection moulding grade

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.596; Matweb PPS data (2026-07)

Reviewed: 2026-07-01

Polypropylene — Copolymer

PP-C

0.895–0.915 g/cm³

905 kg/m³

Random or impact copolymer, injection moulding grade, unfilled

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.254; Harper (2006) p.3.12

Reviewed: 2026-07-01

Polypropylene — Homopolymer

PP

0.899–0.920 g/cm³

905 kg/m³

Injection moulding grade, unfilled

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.254; Matweb PP data (2026-07)

Reviewed: 2026-07-01

Polystyrene — General Purpose

PS

1.040–1.060 g/cm³

1050 kg/m³

General purpose injection moulding grade, unfilled

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.362; Matweb PS data (2026-07)

Reviewed: 2026-07-01

Polystyrene — High Impact

HIPS

1.035–1.045 g/cm³

1040 kg/m³

High-impact injection moulding grade, unfilled

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.362; Harper (2006) p.2.8

Reviewed: 2026-07-01

Polyvinyl Chloride — Rigid

PVC-U

1.380–1.400 g/cm³

1390 kg/m³

Unplasticised injection moulding grade

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.325; Harper (2006) p.3.63

Reviewed: 2026-07-01

Thermoplastic Elastomer (general)

TPE

0.880–1.200 g/cm³

1000 kg/m³

Representative midpoint for injection moulding grades, unfilled

Test: ISO 1183-1 / ASTM D792

Source: Harper (2006) p.3.60; Matweb TPE range (2026-07)

Reviewed: 2026-07-01

Note: Wide range across TPE families (SEBS, SBS, TPO, TPV, COPE, PEBA). Verify against specific grade datasheet.

Thermoplastic Polyurethane

TPU

1.100–1.250 g/cm³

1200 kg/m³

Injection moulding grade, unfilled, polyester-based

Test: ISO 1183-1 / ASTM D792

Source: Brydson (1999) p.779; Matweb TPU data (2026-07)

Reviewed: 2026-07-01

Note: Polyester-based grade. Polyether-based grades are typically 1.05–1.15 g/cm³.

* See individual record notes above.

All values are for unfilled grades unless stated. Filled, reinforced, or blended grades will differ. Always verify against the material supplier's datasheet before use in production calculations.

How the Plastic Part Cost Calculator Works

This plastic material cost calculator converts part geometry into estimated material usage and cost. It takes the part volume from your CAD model, multiplies it by the polymer density to calculate plastic part weight, then applies the resin price per kilogram, production quantity, runner material allocation and a configurable manufacturing allowance to estimate total resin consumption and material cost.

The tool functions as a plastic part weight calculator, a resin cost calculator and an injection moulding cost calculator in a single workflow. It is designed for use in early product design, material comparison, design-for-manufacturability reviews, research projects, preliminary costing and sourcing or RFQ preparation. Any situation where you need to translate part geometry into a plastic part material cost estimate before detailed process costing is available.

1. Part weight

Part weight is calculated by multiplying the part's CAD volume by the material's density. If you enter the volume in mm³ it is first converted to cm³ (÷ 1,000), because density is expressed in g/cm³.

Part weight (g) = part volume (cm³) × density (g/cm³)

2. Runner allocation

In a cold-runner mould, the runner (the channel of solidified plastic connecting the gate to the part cavity) is ejected with each shot and is not part of the finished product. Entering the runner volume allocated per part adds its weight to the total shot weight. Leave this field blank for hot-runner moulds, where no cold runner waste is produced.

Runner weight (g) = runner volume (cm³) × density (g/cm³)
Total shot weight (g) = part weight + runner weight

3. Resin requirement

The total shot weight is multiplied by a material allowance percentage to account for process losses, start-up scrap and other consumption above the finished-part weight. This gives the adjusted material per part. Multiplying by the production quantity and converting to kilograms gives the total resin required.

Adjusted material/part (g) = total shot weight × (1 + allowance ÷ 100)
Resin required (kg) = adjusted material/part × quantity ÷ 1,000

4. Material cost

Material cost is calculated by multiplying the resin required (in kg) by the resin price per kilogram. If a future price is entered, the calculator also shows the projected cost and the absolute and percentage change versus the current price.

Total material cost = resin required (kg) × resin price (S$/kg)
Cost per part = adjusted material/part (g) ÷ 1,000 × resin price (S$/kg)

For Students, Educators and Researchers

The Plastic Part Cost Calculator can also be used as a practical teaching and research tool for manufacturing engineering, mechanical engineering, product design, materials science and polymer-related courses. It helps connect CAD geometry, material density, resin selection and manufacturing economics in a simple, applied way, making it a useful manufacturing engineering calculator for classroom exercises, design assignments and preliminary engineering studies.

What Can This Tool Help Explain?

  • Converting CAD volume into estimated part weight using the relationship between geometry and polymer density
  • Understanding how material density affects component mass, a core concept in materials science and design for manufacturability
  • Comparing the material-cost impact of different thermoplastics using the built-in polymer density calculator
  • Evaluating how runner weight and process waste affect material efficiency and total resin consumption
  • Understanding the effect of production quantity on total resin usage and cost per part
  • Introducing students to injection moulding economics and design-for-manufacturability principles
  • Supporting early-stage project costing, engineering design assignments and CAD volume to weight calculations

Core formula

Part Weight = Part Volume × Material Density

The calculator then applies resin price, production quantity, runner material allocation and relevant manufacturing allowances to estimate total material usage and cost, bridging the gap between part geometry and injection moulding economics.

Disclaimer

This calculator is intended for educational, comparative and preliminary estimating purposes. Actual injection moulding costs depend on additional factors including tooling, machine time, cycle time, labour, energy, scrap rate, secondary operations, quality requirements and production volume. Always verify material properties and cost assumptions using the relevant technical datasheets and source data before using results in formal research or commercial decisions.

Related reading on Plast Plastics Insights

Design for manufacturabilityEngineering thermoplasticsTooling and mould designMicro mouldingPrecision manufacturing

Using This Tool in Teaching or Research?

Lecturers, students and researchers are welcome to use the Plast Plastics Plastic Part Cost Calculator for educational projects, classroom exercises and preliminary engineering studies. If there are additional manufacturing calculators, datasets or reference tools that would support your work, we would be interested to hear what would be useful.

Suggest an Engineering ToolExplore Plast Plastics Insights

Frequently Asked Questions

Can students use this calculator for engineering projects?
Yes. It supports preliminary calculations involving part volume, material density, estimated weight and resin cost, making it a practical tool for manufacturing engineering, mechanical engineering and product design assignments.
Is this calculator suitable for research or academic work?
It can be used for preliminary comparison and educational analysis, but any formal research should verify material properties and cost assumptions using the relevant technical datasheets and source data. The References section below lists the peer-reviewed sources used for the density values in this tool.
Does this calculate the full injection moulding cost?
No. It estimates material-related cost only. Full manufacturing cost also depends on tooling, machine time, cycle time, labour, quality requirements, scrap, energy and secondary processing.
Can different plastic materials be compared?
Yes. Users can compare how differences in material density and resin price affect estimated part weight and material cost. The built-in polymer density calculator includes 21 common injection moulding materials.
What is the difference between part weight and shot weight?
Part weight is the mass of the finished plastic component. Shot weight includes the part weight plus the runner weight: the solidified plastic in the feed channels that is ejected with each cycle in a cold-runner mould. The calculator separates these so you can evaluate material efficiency.

References

Density values used in this calculator are drawn from the following peer-reviewed texts and manufacturer datasheets. All records include a documented grade basis, test method and last-reviewed date. No values are invented or extrapolated without a cited source.

  1. Brydson, J. A. Plastics Materials, 7th ed. Butterworth-Heinemann, Oxford, 1999. ISBN 978-0-7506-4132-6. (Source for PP, PE, ABS, PS, HIPS, PA6, PA66, PC, POM, PMMA, PET, PBT, PEEK, PPS, TPU, PVC-U density ranges.)
  2. Harper, C. A. (ed.) Handbook of Plastics Technologies. McGraw-Hill, New York, 2006. ISBN 978-0-07-146068-4. (Source for PP, PE, ABS, PS, HIPS, PA6, PA66, PC, POM, PMMA, PET, PBT, PEI, TPE density data.)
  3. Victrex plc. PEEK 450G Technical Data Sheet. Victrex, Thornton Cleveleys, UK, 2026. victrex.com. (Source for PEEK density; last reviewed July 2026.)
  4. SABIC. ULTEM™ 1010 Resin Technical Data Sheet. SABIC, Riyadh, 2026. sabic.com. (Source for PEI density; last reviewed July 2026.)
  5. MatWeb LLC. Material Property Data [online database]. MatWeb, Blacksburg VA, 2026. matweb.com. (Cross-reference for PP, HDPE, ABS, PS, PA66, POM-C, PBT, PPS, TPE density ranges; last reviewed July 2026.)

All density values represent unfilled injection moulding grades measured by ISO 1183-1 or ASTM D792 unless otherwise noted. Filled, reinforced, foamed or speciality grades will differ. Always confirm the density of your selected commercial grade using the manufacturer's current technical datasheet before using this calculator for costing decisions.