Thermodynamic Property Calculator — Steam Tables, Refrigerant Properties, Gas and Fluid Thermophysical Data

Thermodynamics Property Calculator
Quick Fluid Selection
Water & Steam
Refrigerants
Air & Atmospheric
Browse All 402 Fluids
Unit System
Lookup Mode
Inputs
Water / Steam (H₂O)
K
Pa
Output Properties
Thermodynamic State
Temperature T K
Pressure P Pa
Density ρ kg/m³
Sp. Volume v m³/kg
Sp. Enthalpy h J/kg
Sp. Int. Energy u J/kg
Sp. Entropy s J/(kg·K)
Heat & Transport
Sp. Heat cp J/(kg·K)
Sp. Heat cv J/(kg·K)
Dyn. Viscosity μ Pa·s
Kin. Viscosity ν m²/s
Thermal Cond. λ W/(m·K)
Thermal Diff. α m²/s
Prandtl Number Pr —
Phase & Saturation
Phase —
Quality x 0–1
Sat. Temp Tsat K
Sat. Press Psat Pa
Sat. Liq. hf J/kg
Sat. Vap. hg J/kg
Latent Heat hfg J/kg
Sat. Liq. sf J/(kg·K)
Sat. Vap. sg J/(kg·K)
Generate Report
Status & Warnings
Ready — enter T and P above to calculate
Graphs

T-sweep at the entered pressure. Select a property to plot after calculating.

P-sweep at the entered temperature. Select a property to plot after calculating.

Saturation envelope and critical point for the selected fluid in T–P space.

Property Tables
T (K) Psat (Pa) ρf (kg/m³) ρg (kg/m³) hf (J/kg) hfg (J/kg) hg (J/kg) sf (J/kg·K) sg (J/kg·K) μf (Pa·s) λf (W/m·K) Prf
Select a fluid and press Calculate to populate the saturation table
Psat (Pa) Tsat (K) ρf (kg/m³) ρg (kg/m³) hf (J/kg) hfg (J/kg) hg (J/kg) sf (J/kg·K) sg (J/kg·K) cp,f (J/kg·K) μf (Pa·s) Prf
Select a fluid and press Calculate to populate the saturation table
T (K) P (Pa) Phase ρ (kg/m³) h (J/kg) s (J/kg·K) cp (J/kg·K) u (J/kg) μ (Pa·s) λ (W/m·K) Pr
Select a fluid and mode, then press Calculate to populate the property grid
Reference Guide — Thermodynamics
01

How KasperCalc Thermodynamics Works

KasperCalc computes thermodynamic properties using a precomputed, structured T/P grid derived from CoolProp 7.2.0 equations of state. Each fluid is solved across a dense mesh — log-spaced in pressure, linearly-spaced in temperature, with adaptive refinement near critical points, saturation curves, and phase boundaries.

Results are stored as compressed lookup tables and served directly in the browser — no server calls, no runtime equation solving, and no internet connection required after the initial page load. The calculator interpolates between precomputed grid points to return property values at arbitrary T and P.

For fluids with a two-phase region, the saturation curve is stored separately at 500 temperature points from Ttriple to Tcrit, with full liquid and vapor properties at each point. Bulk grid properties inside the two-phase dome are stored as NaN; phase behavior is resolved from the saturation table instead.

Accuracy Note: KasperCalc values are grid-interpolated approximations of CoolProp equations of state. Near phase boundaries and critical points, precision is reduced. Results are suitable for engineering estimates and education but should not be used for safety-critical design without independent verification.
Computed Properties (per T/P Node)
  • Density — ρ (kg/m³)
  • Isobaric specific heat — cp (J/kg·K)
  • Isochoric specific heat — cv (J/kg·K)
  • Specific enthalpy — h (J/kg)
  • Specific entropy — s (J/kg·K)
  • Specific internal energy — u (J/kg)
  • Dynamic viscosity — μ (Pa·s)
  • Thermal conductivity — λ (W/m·K)
  • Prandtl number — Pr (dimensionless)
Derived at Display Time
  • Kinematic viscosity — ν = μ/ρ (m²/s)
  • Thermal diffusivity — α = λ/(ρcp) (m²/s)
  • Specific volume — v = 1/ρ (m³/kg)
Phase Flag Codes
FlagPhase Region
0Liquid (subcooled)
1Gas / Supercritical vapor
2Two-phase — bulk NaN; sat. liq/vap stored separately
3Supercritical liquid
4Supercritical gas
255Failed / out-of-range (NaN)
NIST WebBook

Experimental Authority

Authoritative thermophysical and thermochemical database backed by evaluated experimental data. The primary reference standard for validation and benchmark comparisons.

  • ✓ Highest experimental accuracy
  • ✓ Peer-reviewed, documented lineage
  • ✓ Trusted reference standard
  • ✗ Clunky UI
  • ✗ Paid service advertisement
  • ✗ Not designed for engineers
KasperCalc

Fast Browser Lookup

Lightweight, precomputed property database optimized for browser lookup, embedded tools, and offline use. Approximates CoolProp via a structured, pre-solved T/P grid.

  • ✓ Instant browser-native lookup
  • ✓ Works fully offline
  • ✓ SI and US customary units
  • ✓ Deterministic performance
  • ✗ Grid-interpolated (approx.)
  • ✗ Reduced precision near Tcrit
CoolProp

High-Fidelity Physics Engine

Open-source thermophysical library solving equations of state (EOS) on demand. Supports 400+ fluids, refrigerants, incompressible mixtures, and full phase behavior via iterative numerical solvers.

  • ✓ High-fidelity, all phases
  • ✓ Critical & two-phase region
  • ✓ 400+ fluids & mixtures
  • ✗ Requires Python / C++
  • ✗ Computational overhead
  • ✗ Not browser-native
Temperature Axis

500 linearly-spaced points from Tmin to Tmax, plus 50 adaptive points clustered within ±20% of Tcrit. Total: up to ~530 unique T-points per fluid.

Pressure Axis

200 log-spaced points from Ptriple (or 101,325 Pa) to Pmax, plus 50 linear points within ±20% of Pcrit, plus a guaranteed 101,325 Pa (1 atm) point. Total: up to ~240 unique P-points per fluid.

Pressure Bands

The pressure axis is divided into bands of 20 pressure points each to enable partial-file loading. Each band is stored as a separate .bin and .json file. A fluid with 240 pressure points has ~12 bands.

Saturation Curve

500 temperature points from Ttriple to Tcrit. Both saturated liquid (Q=0) and saturated vapor (Q=1) properties stored at each point: density, cp, enthalpy, entropy, viscosity, and conductivity.

Incompressible Fluids (INCOMP)

INCOMP fluids (always single-phase liquid) use the same T/P grid structure but are evaluated via PropsSI with the full fluid string (e.g. INCOMP::MEG[0.3]). No saturation curve. cv is stored as NaN. Phase flag is always 0 (liquid).

File Format
FileContentsFormat
meta.jsonFluid metadata, T/P axes info, band list, critical & triple pointsJSON (UTF-8)
meta.binSame as meta.json (UTF-8 encoded)Raw bytes
grid_band_NNN_*.binGrid property data: T, P, rho, cp, cv, h, s, u, visc, cond, Pr, phase flagFloat32 × 11 + uint8
saturation.binSaturation curve: T, P, liq/vap density, cp, h, s, visc, cond + phase flagFloat32 × 14 + uint8
Float32 Precision

All grid and saturation values are stored as 32-bit IEEE 754 floats (~7 significant decimal digits). This is sufficient for engineering calculations but introduces small rounding errors relative to CoolProp double-precision output.

NaN Encoding

Failed or undefined properties (two-phase bulk, out-of-range, INCOMP cv) are stored as IEEE 754 NaN in binary files and as JSON null in text files.

Typical grid sizes: Water: ~104,000 grid points. R-134a: ~93,000 grid points. A simple incompressible fluid (e.g. MEG[0.3]): ~100,500 grid points.
Water & Steam
Water (H₂O) Water Heavy Water (D₂O) HeavyWater
Light Gases & Noble Gases
Air (pseudo-pure) Air Nitrogen (N₂) Nitrogen Oxygen (O₂) Oxygen Hydrogen (H₂) Hydrogen Parahydrogen ParaHydrogen Deuterium (D₂) Deuterium Helium (He) Helium Neon (Ne) Neon Argon (Ar) Argon Krypton (Kr) Krypton Xenon (Xe) Xenon Fluorine (F₂) Fluorine
Inorganic Compounds
Ammonia (NH₃) Ammonia Carbon Dioxide (CO₂) CarbonDioxide Carbon Monoxide (CO) CarbonMonoxide Carbonyl Sulfide (COS) CarbonylSulfide Hydrogen Chloride (HCl) HydrogenChloride Hydrogen Sulfide (H₂S) HydrogenSulfide Nitrous Oxide (N₂O) NitrousOxide Sulfur Dioxide (SO₂) SulfurDioxide Sulfur Hexafluoride (SF₆) SulfurHexafluoride
Alkanes (Paraffins) — C1 through C10
Methane (CH₄) Methane Ethane (C₂H₆) Ethane Propane (C₃H₈) Propane n-Butane n-Butane Isobutane IsoButane n-Pentane n-Pentane Isopentane Isopentane Neopentane Neopentane n-Hexane n-Hexane n-Heptane n-Heptane n-Octane n-Octane n-Nonane n-Nonane n-Decane n-Decane
Cyclic Hydrocarbons & Aromatics
Cyclopropane CycloPropane Cyclopentane Cyclopentane Cyclohexane CycloHexane Benzene (C₆H₆) Benzene Toluene (C₇H₈) Toluene Ethylbenzene EthylBenzene m-Xylene m-Xylene o-Xylene o-Xylene p-Xylene p-Xylene
Alkenes, Alkynes & Dienes
Ethylene (C₂H₄) Ethylene Propylene (C₃H₆) Propylene 1-Butene 1Butene cis-2-Butene cis-2-Butene trans-2-Butene trans-2-Butene Isobutene IsoButene Propyne Propyne Propadiene Propadiene
Oxygenates, Alcohols & Ethers
Methanol (CH₃OH) Methanol Ethanol (C₂H₅OH) Ethanol Acetone (C₃H₆O) Acetone Dimethyl Ether DimethylEther Diethyl Ether DiethylEther Dimethyl Carbonate DimethylCarbonate Methyl Formate MethylFormate
Siloxanes (Organic Silicon Compounds)
MM (hexamethyldisiloxane) MM MDM (octamethyltrisiloxane) MDM MD2M (decamethyltetrasiloxane) MD2M MD3M MD3M MD4M MD4M D4 (cyclo-octamethyltetrasiloxane) D4 D5 (cyclo-decamethylpentasiloxane) D5 D6 (cyclo-dodecamethylhexasiloxane) D6
Fatty Acid Methyl Esters (Biodiesel / FAME)
Methyl Linoleate MethylLinoleate Methyl Linolenate MethylLinolenate Methyl Oleate MethylOleate Methyl Palmitate MethylPalmitate Methyl Stearate MethylStearate
Refrigerants — CFC / HCFC (Legacy, Phase-Out)
R-11 (CCl₃F) R11 R-12 (CCl₂F₂) R12 R-13 (CClF₃) R13 R-14 (CF₄) R14 R-21 (CHCl₂F) R21 R-22 (CHClF₂) R22 R-23 (CHF₃) R23 R-113 (C₂Cl₃F₃) R113 R-114 (C₂Cl₂F₄) R114 R-115 (C₂ClF₅) R115 R-123 R123 R-124 R124 R-141b R141b R-142b R142b R-152a R152A R-161 R161 RC-318 (cyclo-C₄F₈) RC318
Refrigerants — HFC (Hydrofluorocarbons)
R-32 (CH₂F₂) R32 R-41 (CH₃F) R41 R-116 (C₂F₆) R116 R-125 (CHF₂CF₃) R125 R-134a (CH₂FCF₃) R134a R-143a (CH₃CF₃) R143a R-218 (C₃F₈) R218 R-227ea (CF₃CHFCF₃) R227EA R-236ea R236EA R-236fa R236FA R-245ca R245ca R-245fa R245fa R-365mfc R365MFC
Refrigerants — HFO (Hydrofluoroolefins, Low-GWP)
R-1234yf (CF₃CF=CH₂) R1234yf R-1234ze(E) (trans) R1234ze(E) R-1234ze(Z) (cis) R1234ze(Z) R-1243zf R1243zf R-1233zd(E) R1233zd(E) R-1336mzz(E) R1336mzz(E) R-1336mzz(Z) R1336mzz(Z) R-1123 (CF₂=CHF) R1123 R-13I1 (CF₃I) R13I1
Refrigerant Blends (Pseudo-Pure)
R-404A (R125/R134a/R143a) R404A R-407C (R32/R125/R134a) R407C R-410A (R32/R125) R410A R-507A (R125/R143a) R507A
INCOMP — Pure Incompressible Heat Transfer Fluids (~74 fluids)

Single-phase liquid fluids evaluated via the INCOMP backend. No saturation curve. cv = NaN. Phase is always 0 (liquid). These include aviation heat transfer fluids, silicone oils, Therminol series, and industrial brines.

AS10, AS20, AS30 (aviation) AS40, AS47, AS55 (aviation) DEB, DSF (diethylbenzene, dowtherm SF) HC10, HC2, HC2L, HC50, HC5L (hydrocarbons) HFE-7100, HFE-7200, HFE-7500, HFE-7600 HIGHFREEZER55, HIGHFREEZER60, HIGHFLOW20 Marlotherm N, Marlotherm SH NaK (sodium-potassium alloy) PAG46 (polyalkylene glycol oil) SH70, SH72, SH105, SH110, SH200 (silicone oils) SilTherm (silicone heat transfer) T66, T73, TC4, TX22 Therminol 59, 66, D12, VP-1, XP Xceltherm 600, MK1, XT
INCOMP — Aqueous Mixtures with Concentration [0.0–1.0]

Mixture fluids accessed as INCOMP::BaseFluid[massFraction], e.g. INCOMP::MEG[0.3] for 30% Mono-Ethylene Glycol. Concentrations outside the valid range return NaN (phase=255).

MEG — Mono-Ethylene Glycol / Water MEG MEG2 — EG / Water (alt formulation) MEG2 MPG — Mono-Propylene Glycol / Water MPG AEG — Ethylene Glycol / Water (automotive) AEG APG — Propylene Glycol / Water (aircraft) APG MEA / MEA2 — Mono-Ethanolamine / Water MEA MCA / MCA2 — Calcium Chloride / Water MCA MAM / MAM2 — Ammonium Chloride / Water MAM MGL — Glycerol / Water MGL MGP — Glycerol / Propylene Glycol MGP MK / MKA / MKF — Potassium Acetate/Formate / Water MK GKN / AKF — Potassium Acetate / Water GKN AN — Ammonium Nitrate / Water AN AL — Lithium Chloride / Water AL LiBr — Lithium Bromide / Water LiBr MLO — LiBr / Organic Solvent MLO MMG — Magnesium Chloride / Water MMG MNaK — NaCl+KCl / Water MNaK MSZ — Sodium Chloride / Water (brine) MSZ MVG — Vinyl Glycol / Water MVG MWM — EG / Water (high-temp) MWM MXP — PG / Water (extended) MXP MRC — Refrigerant mixture MRC MMA — Methyl Acetate / Methanol MMA PK2 / PKL — Potassium Carbonate/Lactate PK2 ZAC / ZFC / ZLC — Zinc Acetate/Formate/Lactate ZAC ZM / ZMC — Zinc mixtures ZM
Derived Properties (Computed at Display Time)
Specific Volume v = 1 / ρ   [m³/kg]
Kinematic Viscosity ν = μ / ρ   [m²/s]
Thermal Diffusivity α = λ / (ρ · cp)   [m²/s]
Prandtl Number Pr = μ · cp / λ   [dimensionless] Pr = ν / α   (alternate form)
Saturation & Quality
Quality (Dryness Fraction) x = (h − hf) / hfg   [0–1] where hfg = hg − hf  (latent heat)
Two-Phase Mixture Properties h = hf + x · hfg s = sf + x · sfg v = vf + x · vfg
Clausius-Clapeyron Equation dP/dT = hfg / (T · vfg) Relates slope of saturation curve to latent heat
Ideal Gas Relations
Ideal Gas Law P v = R T   or   P = ρ R T R = R𝕄 / M   (specific gas constant)
Mayer Relation cp − cv = R   [J/(kg·K)]
Heat Capacity Ratio γ = cp / cv   [dimensionless] Air: γ ≈ 1.4   Steam: γ ≈ 1.3
First & Second Law of Thermodynamics
First Law (Closed System) dh = du + d(Pv) = δq + v dP
First Law (Open/Flow System) q − w = Δh + ΔKE + ΔPE For pumps & turbines: w = hin − hout
Second Law / Entropy Relations T ds = du + P dv   (1st Gibbs equation) T ds = dh − v dP   (2nd Gibbs equation) ds ≥ δq / T   (Clausius inequality)
Isentropic Processes (Ideal, Reversible Adiabatic)
Isentropic Relations (Ideal Gas) T2/T1 = (P2/P1)(γ−1)/γ T2/T1 = (v1/v2)γ−1
Isentropic Efficiency (Turbine) ηT = (h1−h2) / (h1−h2s)
Isentropic Efficiency (Compressor) ηC = (h2s−h1) / (h2−h1)
Heat Transfer Dimensionless Numbers
Reynolds Number Re = ρ V D / μ = V D / ν
Nusselt Number Nu = hconv D / λ
Stanton Number St = Nu / (Re · Pr) = hconv / (ρ V cp)
Note: Subscripts f and g denote saturated liquid and saturated vapor respectively. Subscript fg denotes the difference (g − f). Subscript s denotes isentropic (reversible adiabatic) conditions.
The calculator offers six unit presets. Each preset applies a consistent set of conversions to every displayed output: temperature, pressure, energy, transport properties, and so on. The raw data is always stored in base SI (CoolProp native); unit conversion happens at display time, so you can switch presets without re-running a calculation.
Side-by-Side Unit Comparison
Property SI Strict SI Engineering US Customary US Process-HVAC Textbook SI Textbook US
Temperature K °C °F °F °C °F
Pressure Pa kPa psia psia kPa psia
Density kg/m³ kg/m³ lbm/ft³ lbm/ft³ kg/m³ lbm/ft³
Spec. Volume m³/kg m³/kg ft³/lbm ft³/lbm m³/kg ft³/lbm
cp / cv J/(kg·K) kJ/(kg·K) BTU/(lbm·°R) BTU/(lbm·°F) kJ/(kg·K) BTU/(lbm·°R)
Enthalpy (h) J/kg kJ/kg BTU/lbm BTU/lbm kJ/kg BTU/lbm
Entropy (s) J/(kg·K) kJ/(kg·K) BTU/(lbm·°R) BTU/(lbm·°R) kJ/(kg·K) BTU/(lbm·°R)
Int. Energy (u) J/kg kJ/kg BTU/lbm BTU/lbm kJ/kg BTU/lbm
Dyn. Viscosity Pa·s mPa·s lbm/(ft·s) cP Pa·s cP
Conductivity W/(m·K) W/(m·K) BTU/(hr·ft·°F) BTU/(hr·ft·°F) W/(m·K) BTU/(hr·ft·°F)
Prandtl dimensionless
Preset Descriptions
SI Strict
All outputs exactly as returned by CoolProp (no conversion applied). Temperature in Kelvin, pressure in Pascals, energies in J/kg. Best for verifying raw data, feeding other software, or writing equations where absolute temperature is required. Entropy and enthalpy offsets are CoolProp reference-state values; treat absolute numbers as deltas only.
SI Engineering
Practical metric units standard in European and international engineering practice. Temperature shifts to °C for intuitive feel; pressures scale to kPa; energies scale to kJ/kg. Viscosity displayed in mPa·s (= cP numerically), which is more legible for liquids than Pa·s. Matches the output style of most modern SI-based engineering textbooks and process simulators.
US Customary
Traditional US engineering units used in mechanical, aerospace, and general US practice. Pressure in psia (absolute), density in lbm/ft³, energies in BTU/lbm. Viscosity in lbm/(ft·s) for use with the BTU/ft/hr system. Consistent with ASHRAE fundamentals handbooks and many US mechanical engineering references.
US Process-HVAC
Tuned for process engineering and HVAC applications in the United States. Matches US Customary in most respects, but viscosity is displayed in centipoise (cP). This is the universal industrial standard found in Perry's, GPSA, and most process datasheets and specific heat labels °F in the denominator (numerically identical to °R for Δ values). Common in oil & gas, refrigeration, and building systems work.
Textbook SI
Matches the conventions of leading thermodynamics textbooks in SI edition: Çengel & Boles, Moran & Shapiro, Smith, Van Ness & Abbott. Temperature in °C, pressure in kPa, energies in kJ/kg, entropy in kJ/(kg·K). Viscosity kept in Pa·s (= kg/(m·s)) as shown in most textbook tables. Ideal for checking homework or worked examples against a reference book.
Textbook US
Matches US-edition thermodynamics textbooks: Çengel & Boles (US), Faires & Simmang, and steam tables common in US universities. Temperature in °F, absolute temperature in °R where needed, pressure in psia, energies in BTU/lbm. Viscosity in cP for readability. Entropy uses °R in the denominator to match steam table formatting. Use this when cross-referencing textbook appendix tables.
Absolute vs. Relative Temperature: BTU/lbm·°R and BTU/lbm·°F are numerically identical for differences (Δ1 °F = Δ1 °R), but absolute temperature for ideal-gas or isentropic calculations always requires Rankine (°R) or Kelvin (K). The calculator uses the correct absolute scale internally regardless of the display preset.
Tip: cP (centipoise) = mPa·s exactly. 1 cP = 0.001 Pa·s. Water at 20 °C ≈ 1.002 cP. This equivalence makes it easy to switch between US Process and SI Engineering viscosity values with no arithmetic.

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