Engineering Reference

Specific Heat Capacity Chart

Specific heat capacity for 45 liquids, gases, metals, plastics and building materials, in J/kg·K and BTU/lb·°F — the number that decides how much heat a material stores.

Data verified 2026-09-29 · based on NIST Standard Reference Database 69, 2023 release

Quick Answer

Water has the highest specific heat of any common material at 4 182 J/kg·K, which is why it is the default coolant. Air is 1 005, carbon steel 490, aluminium 900 and copper 385. Metals are low — a metal part heats and cools quickly for a given heat input, which is what makes them good heat sinks.

Specific Heat Capacity of Common Materials

Material[1]Class[1]Specific heat
J/kg·K[1]
Specific heat
BTU/lb·°F[2]
Note[1]
Water (liquid, 20 °C) #Liquid41820.9989Unusually high — the reason water is a good coolant
Sea water #Liquid39930.9537Slightly lower than fresh water because of the dissolved salts
Ethanol #Liquid24400.5828About 58% of water's
Methanol #Liquid25300.6043Similar to ethanol
Glycerol #Liquid24300.5804Viscous; poor coolant despite a reasonable specific heat
Ethylene glycol #Liquid24100.5756Used as an antifreeze base
Hydraulic oil #Liquid19000.4538Typical figure; mineral oils cluster near 1 900
Engine oil #Liquid20000.4777Typical figure at 20 °C
Mercury #Liquid1400.03344Very low — mercury heats quickly for a given heat input
Hydrogen #Gas143043.416Highest specific heat of any gas
Helium #Gas51931.24Second highest
Water vapour (steam) #Gas20100.4801About half of liquid water
Air (dry, constant pressure) #Gas10050.24The reference for HVAC and cooling calculations
Nitrogen #Gas10400.2484Close to air, as expected of its main component
Oxygen #Gas9180.2193Slightly below nitrogen
Carbon dioxide #Gas8440.2016Below the diatomic gases
Methane #Gas22200.5302Natural gas; high for a fuel gas
Aluminium #Metal9000.215High for a metal — why aluminium heats and cools quickly
Copper #Metal3850.09196Low, but its thermal conductivity is high, so it still works as a heat sink
Brass #Metal3800.09076Similar to copper
Silver #Metal2350.05613Lowest of the common metals
Gold #Metal1290.03081Very low
Carbon steel #Metal4900.117The standard figure for steelwork
Stainless steel 304 #Metal5000.1194Slightly higher than carbon steel
Cast iron #Metal4600.1099Similar to steel
Titanium #Metal5230.1249Higher than steel
Magnesium #Metal10240.2446High for a structural metal
Zinc #Metal3880.09267Similar to brass
Lead #Metal1280.03057Very low, with a high density — lead heats slowly and holds little heat
Nickel #Metal4440.106Similar to steel
Tungsten #Metal1340.03201Low, like the other refractory metals
Concrete #Building material8800.2102Typical for normal-weight concrete
Glass #Building material8400.2006Soda-lime glass
Gypsum board #Building material10900.2603Higher than concrete or glass, because of the water of crystallisation
Wood (pine, dry) #Building material17000.406Dry wood; moisture raises it sharply
Brick #Building material8400.2006Typical fired clay brick
PVC #Plastic10000.2388Typical figure for rigid PVC
Nylon 6/6 #Plastic16700.3989Moisture raises it further
Acetal (POM) #Plastic14600.3487Typical figure
Polyethylene #Plastic19000.4538Higher than most engineering plastics
Polypropylene #Plastic19200.4586Similar to polyethylene
PTFE #Plastic10000.2388Typical figure
PEEK #Plastic13400.3201Typical figure
Polystyrene #Plastic13000.3105Typical figure
Air (constant volume, cv) #Gas7180.1715The constant-volume value, for closed-vessel calculations

Values are for 20 °C and constant pressure unless the row says otherwise. Specific heat is not constant — it rises with temperature for most solids, and for gases it differs between constant pressure (cp) and constant volume (cv), with the ratio between them setting the speed of sound. The table lists both air values because the difference matters: 1 005 J/kg·K is the constant-pressure figure used for airflow and HVAC work, and 718 is the constant-volume figure used for closed vessels and compressors.

What Specific Heat Actually Tells You

Specific heat is the energy needed to raise one kilogram of a material by one kelvin. It answers two questions that come up constantly in design work: how much heat will this part absorb before its temperature rises, and how much energy will this material store.

The governing relationship is Q = m·cp·ΔT. The mass is the whole part, not the surface — a copper heat sink has a lower specific heat than an aluminium one, but copper's density is 3.3 times higher, so a copper sink of the same volume stores about 1.4 times as much heat per degree. This is why thermal mass calculations need density as well as specific heat, and why comparing specific heats alone can mislead.

The related quantity is volumetric heat capacity, which is density × specific heat. Water's is 4.18 MJ/m³·K, the highest of any common material — about twice concrete's and 3 300 times air's. That single figure explains why water is the default heat-transfer fluid, why hydronic heating works at all, and why a building with concrete floors holds its temperature so much longer than one with timber floors.

Why Metals Feel Cold and Wood Feels Warm

The sensation of temperature when you touch a material is governed by how fast heat leaves your hand, not by the material's temperature. Both a steel plate and a wooden board at 20 °C are at the same temperature; the steel feels colder because it draws heat from your skin far faster.

Two properties drive that: thermal diffusivity, which combines conductivity, density and specific heat, and the volumetric heat capacity. Steel's thermal conductivity is roughly 50 W/m·K against wood's 0.15 — a factor of 300 — and that dominates. The specific heat column is part of the explanation but rarely the main part.

The same reasoning applies to tooling and to machining. A low specific heat means a small energy input produces a large temperature rise, which is one reason titanium (523 J/kg·K) is so difficult to machine: the heat generated by cutting stays in the chip and the tool instead of being carried away by a large thermal mass. Aluminium, at 900 J/kg·K and with three times the thermal conductivity, carries heat away far more effectively and cuts much cooler.

Frequently Asked Questions

What is the specific heat of water?
4 182 J/kg·K at 20 °C — the highest of any common material, and the reason water is the default heat-transfer fluid. In imperial units that is almost exactly 1.0 BTU/lb·°F, which is not a coincidence: the BTU was originally defined as the heat needed to raise one pound of water by one degree Fahrenheit. Water's specific heat varies slightly with temperature, reaching about 4 218 J/kg·K at 0 °C.
Why do metals have low specific heat?
Because heat energy in a metal is stored mainly in the vibration of a small number of heavy atoms rather than in molecular bonds. Aluminium at 900 J/kg·K is the highest of the common metals, copper is 385 and lead only 128. The practical effect is that metal parts heat and cool quickly — good for heat sinks that must respond fast, poor for thermal storage.
What is the difference between cp and cv?
cp is specific heat at constant pressure and cv at constant volume. They are equal for solids and liquids, and differ for gases by the work the gas does as it expands — air's cp is 1 005 J/kg·K and its cv is 718, a ratio of 1.4. Use cp for open systems and airflow, and cv for closed vessels and compressor calculations.
How do I calculate how much heat a part absorbs?
Q = m·cp·ΔT. So a 2 kg aluminium block (cp = 900) absorbing 180 kJ of heat rises by 180 000 ÷ (2 × 900) = 100 K. For a part where mass matters more than specific heat, compare volumetric heat capacity instead — density × cp. Aluminium's is 2.43 MJ/m³·K and copper's 3.44, which is why a copper heat sink of the same volume stores more heat.
Which material stores the most heat per unit volume?
Water, at about 4.18 MJ/m³·K. Among solids, copper reaches 3.44 MJ/m³·K thanks to its high density, and concrete about 2.1. Air is 1.2 kJ/m³·K — 3 400 times less than water — which is why air-based thermal storage needs enormous volumes and why water or a phase-change material is used instead wherever space is limited.

Related

Value Sources

Each data column on this page is tied to the source it came from. The numbers in square brackets correspond to the table headers above.

#SourceTypeRevision / method
[1]Published specific heat capacities for engineering materialsstandardcompilations as published 2024–2026
[2]Specific heat converted to BTU/lb·°FderivedBTU/lb·°F = J/kg·K ÷ 4186.8, the exact conversion. Checked at build time for every row.

Data Sources

StandardRevisionWhat it covers on this page
NIST Chemistry WebBook — thermophysical propertiesNIST Standard Reference Database 69, 2023 releasethe gas and liquid values
ASME / handbook specific heat values for engineering solidscompilations as published 2024–2026the metal, plastic and building material values
ASHRAE Handbook — FundamentalsASHRAE Handbook, 2021 Fundamentals volumethe HVAC-relevant values for air, water and refrigerants

Cross-checked against:

Derived values — the following values on this page are calculated, not taken directly from the standard:

ValueHow it is derived
Specific heat in BTU/lb·°FJ/kg·K ÷ 4186.8, exact. Water is held as a known-value check at 0.9988 to confirm the reference conversion is being applied correctly.

Values are for 20 °C at constant pressure. Specific heat varies with temperature — for solids it generally rises — and for gases the constant-pressure and constant-volume values differ substantially. Values for alloys, plastics and building materials are typical figures for the class; a specific grade's data sheet should be used where the heat balance is critical.

Accuracy and use. The values on this page are compiled from the published standards and cross-checked sources listed above. Where values are derived, the derivation is stated. No warranty, express or implied, is made as to the accuracy or completeness of this information, and no liability is accepted for any loss or damage arising from its use. Engineering reference data is provided for guidance in preliminary work — before a value is used for design, fabrication or acceptance testing, verify it against the current revision of the governing standard and against your own inspection. The user assumes all risk and responsibility in connection with the use of this information.

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