Density Table of Plastics and Polymers

This calculator is a fast reference tool for people who need density values for plastics and polymers without digging through scattered data sheets. It is built for quick checks, simple comparisons, and everyday work. The default setup uses Imperial units, so the numbers are ready for U.S. users right away.

The main idea is simple. Pick a material, choose the temperature and pressure you want, and the calculator shows the density and specific volume. It also updates the graphs so the user can see how the material changes across a range. No extra steps. No clutter. Just a clean tool for practical use.

What this calculator is for

This tool is helpful when a project needs a quick density check for a plastic part, a polymer sample, or a material comparison. It is useful in design, manufacturing, shop work, product planning, and general reference work. It is also helpful when the user needs a fast answer before moving to a deeper material lookup.

The calculator is not trying to replace a full engineering database. It is meant to make common decisions easier. If the job is simple, this tool gets the answer fast. If the job needs deeper certification data, the calculator still gives a solid starting point.

How to use it

1. Choose a material from the material list.
2. Set the unit system with the unit selector. Imperial is the default.
3. Enter the temperature.
4. Enter the pressure.
5. Read the density and specific volume in the top table.
6. Check the graphs to see how density shifts with temperature and pressure.
7. Use the screenshot button to save the screen as an image.

That is the whole workflow. The calculator does the conversion work in the background, so the user can stay focused on the result instead of the math.

What the unit selector changes

The unit selector affects the full calculator at once. It does not only change one label. It changes the temperature input, pressure input, density output, specific volume output, and the graph labels. That means the entire screen stays consistent.

In Imperial mode, the calculator uses:

• Temperature in °F
• Pressure in psi
• Density in lb/ft³
• Specific volume in ft³/lb

In Metric mode, the calculator uses:

• Temperature in °C
• Pressure in MPa
• Density in kg/m³
• Specific volume in m³/kg

Since the default is Imperial, the screen opens in the format most familiar to U.S. users.

Why density matters

Density tells how much mass is packed into a given volume. A denser plastic usually feels heavier for its size. A lighter plastic may be easier to handle, easier to float, or better for weight-sensitive parts. Density also helps with material matching, shipping estimates, and volume-to-weight planning.

Specific volume is the opposite idea. It tells how much space 1 unit of mass takes up. When density goes up, specific volume goes down. When density goes down, specific volume goes up. The calculator shows both, which makes comparisons easier.

Simple formulas used in the calculator

The formulas are kept simple on purpose. No advanced math is needed to use the tool.

Density from temperature:

density at temperature = base density / [1 + thermal factor × temperature change]

Density from pressure:

final density = density after temperature change × [1 + pressure change / bulk stiffness]

Specific volume:

specific volume = 1 / density

Temperature change means the difference between the entered temperature and the reference temperature. Pressure change means the difference between the entered pressure and the reference pressure.

Example

Here is a plain example using Imperial units. Material: ABS. Temperature: 68 °F. Pressure: 14.5 psi

The calculator uses the material reference value and adjusts it for the entered temperature and pressure. Since 68 °F is the same as the common room reference point, the temperature adjustment is minimal. At near-normal pressure, the density stays close to the base value.

A typical result for ABS in this case is about:

Density: 65.0 to 66.0 lb/ft³

Specific volume: 0.0151 to 0.0154 ft³/lb

The exact value depends on the material settings in the calculator and the chosen material grade. The point of the example is the workflow. Select the material, enter the values, and read the result at the top.

Quick material reference in Imperial units

The table below gives a practical quick-look density guide in Imperial units. These values are useful for checking whether a result looks reasonable.

Material	Density, lb/ft³	Specific volume, ft³/lb	Typical use note
ABS	65.0	0.0154	General purpose plastic with balanced strength
PLA	77.4	0.0129	Common 3D printing material
Nylon, Kaprolon	71.8	0.0139	Wear parts and machine components
LDPE	57.4	0.0174	Soft, flexible, low density plastic
HDPE	59.3	0.0169	Containers, pipes, and durable goods
Polypropylene	56.8	0.0176	Lightweight and chemically resistant
Polystyrene	65.6	0.0152	Rigid, common, easy to process
HIPS	65.3	0.0153	Impact-modified polystyrene
PET	86.2	0.0116	Bottles, packaging, and technical parts
PETG	79.4	0.0126	Clear parts and print-friendly material
PMMA	73.7	0.0136	Clear plastic with good optical use
Polycarbonate	74.9	0.0133	High impact strength and toughness
Rigid PVC	86.2	0.0116	Pipes, profiles, and industrial parts
Flexible PVC	78.2	0.0128	Soft and flexible formulations
POM Acetal	88.1	0.0114	Precision parts, gears, and bearings
PA6	70.9	0.0141	Nylon family, general engineering use
PA66	71.5	0.0140	Strong nylon grade for technical parts
PTFE	137.4	0.0073	Low friction and chemical resistance
PBT	81.7	0.0122	Stable engineering thermoplastic
TPE	68.7	0.0146	Elastic and rubber-like plastic
TPU	73.7	0.0136	Flexible and abrasion resistant
SAN	67.4	0.0148	Transparent and stiff
PEEK	82.3	0.0121	High-performance engineering plastic
PPS	83.5	0.0120	Heat-resistant industrial material
PVDF	111.2	0.0090	Chemical resistance and process use
ASA	66.8	0.0150	Outdoor-friendly, weather-resistant plastic
ABS+PC	69.9	0.0143	Blend of toughness and stiffness
Epoxy Resin	71.8	0.0139	Common thermoset resin system
Bakelite	84.3	0.0119	Classic thermoset material
Polyamide	71.8	0.0139	General nylon family reference

Unit conversion reference

The calculator handles conversions automatically, but a reference table is still useful for quick checks.

From	To	Conversion	Easy use note
°F	°C	(°F – 32) × 5 / 9	Used for Imperial temperature entry behind the scenes
°C	°F	(°C × 9 / 5) + 32	Helpful for switching to Imperial view
psi	MPa	psi × 0.006894757	Pressure conversion into metric form
MPa	psi	MPa × 145.0377	Pressure conversion into Imperial form
lb/ft³	kg/m³	lb/ft³ × 16.0185	Density conversion for metric display
kg/m³	lb/ft³	kg/m³ × 0.062428	Density conversion for Imperial display
ft³/lb	m³/kg	ft³/lb × 0.062428	Specific volume conversion to metric
m³/kg	ft³/lb	m³/kg × 16.0185	Specific volume conversion to Imperial

Common temperature and pressure entry guide

The calculator accepts a wide range of input values. For normal everyday work, the table below can help with fast setup.

Situation	Temperature	Pressure	What to expect
Room reference	68 °F	14.5 psi	Good standard comparison point
Cool indoor storage	50 °F	14.5 psi	Density often shifts slightly upward
Warm shop area	86 °F	14.5 psi	Density often shifts slightly downward
Hot process check	122 °F	14.5 psi	Useful for heat-sensitive plastics
Light pressure increase	68 °F	29.0 psi	Small density increase in most materials
Moderate pressure increase	68 °F	72.5 psi	Useful for pressure trend comparison
Higher pressure test	68 °F	145.0 psi	Shows stronger pressure effect
Hot and pressurized	140 °F	145.0 psi	Good stress-test style scenario

How to read the result table

The top table shows 2 key values. Density appears on the left. Specific volume appears on the right. Density is the main number most users care about. Specific volume is useful when the job is volume-based instead of weight-based. A higher density number means the material is heavier for the same amount of space. A lower specific volume number means the same thing from the opposite angle. These 2 values always move in opposite directions.

How to use the graphs

The calculator includes 2 graphs. One shows density against temperature. The other shows density against pressure. These graphs help the user see whether the material is stable or changing quickly across the chosen range.

The temperature graph is useful when a part will run hot, cool down, or move between different environments. The pressure graph is useful when the material is under load or when the process pressure matters.

The red point on each graph marks the current setting. That makes it easy to connect the numbers in the input fields with the visual curve.

What the material list is for

The material list is the fastest way to switch between plastics. It is not only a name list. It also changes the density behavior and the graph shape. This makes it easier to compare common materials without opening a separate reference sheet.

Some materials in the list are general-purpose plastics. Some are engineering plastics. Some are flexible materials. Some are high-performance grades. That is why the density values vary so much across the list.

Practical use cases

This calculator is useful for:

• Choosing a plastic for a lightweight part
• Estimating part weight from volume
• Comparing similar plastics side by side
• Checking whether a number looks realistic
• Preparing a product page or catalog note
• Making quick material reference checks in production or design

Quick comparison notes

Some simple patterns are worth remembering.

• Polypropylene is one of the lighter common plastics.
• ABS and polystyrene sit in the middle range.
• PET, POM, and PVC are usually denser than ABS.
• PTFE is much denser than most common plastics.
• Foam and filled plastics can be very different from standard grades.

That is why a reference calculator is so useful. It gives a fast first check before deeper analysis.

Reading the output like a pro

A good habit is to compare the result with the material name, the temperature, and the pressure all at once. Density alone does not tell the full story. A change in heat can move the number slightly. A change in pressure can also push it up. The calculator shows the result after both effects are applied.

For most everyday checks, the number in the top table is all that is needed. For comparison work, the graph is the second layer of value. Together, they give a clean picture without forcing the user to do manual math.

What makes this tool easy to use

The layout is compact. The default unit system is Imperial. The controls are direct. The result updates right away. There is no need to hunt through menus or convert values by hand. That is what makes this calculator practical for fast reference work.

The unit selector controls everything at once, which keeps the interface simple. The user does not need to remember which field is in which system. The whole screen stays aligned with the chosen format.

This calculator is designed for quick reference, not full lab certification. Real-world plastics can vary by grade, fillers, additives, moisture, processing method, and supplier. That is normal. For final engineering sign-off, a data sheet from the exact grade is still the safest source. Even with that limitation, the calculator is still very useful. It gives a clear answer fast and helps narrow down the next step.

Literature

• ASTM D792, Standard Test Methods for Density and Specific Gravity of Plastics by Displacement
• MatWeb Material Property Data
• Engineering ToolBox, Density of Plastics
• Plastics Handbook, general engineering reference editions
• Modern Plastics Encyclopedia, material property reference sections
• Manufacturer technical data sheets for specific resin grades