Specific heat capacity of liquid water

c_{p,\mathrm{water}} = 4,181.3\ \text{J/(kg}{\cdot}\text{K)}

Value	4.1813 kJ/(kg·K) (4,181.3 J/(kg·K)) Use in the calculator →
Status	Reference value; the source states no uncertainty
Source	IAPWS-95 (IAPWS R6-95(2018)), computed with CoolProp at 298.15 K and 0.1 MPa
Categories	Thermodynamic Material Properties

Specific heat capacity of liquid water in every specific heat capacity unit

Unit	Value
kilojoule per kilogram-kelvin	4.1813 kJ/(kg·K)
joule per kilogram-kelvin	4,181.3 J/(kg·K)
BTU per pound-Fahrenheit	0.99868635 BTU/(lb·°F)
joule per kilogram-Celsius	4,181.3 J/(kg·°C)
foot pound-force per pound-Rankine	777.14702 ft·lbf/(lb·°R)
kilojoule per kilogram-Celsius	4.1813 kJ/(kg·°C)
joule per gram-kelvin	4.1813 J/(g·K)
calorie per gram-Celsius	0.99935468 cal/(g·°C)
kilocalorie per kilogram-Celsius	0.99935468 kcal/(kg·°C)
BTU per pound-Rankine	0.99868635 BTU/(lb·°R)

This value moves with temperature

Water at any temperature

0 to 100 °CThe value above is one point on this curve. Liquid water from 0 to 100 °C at 1 atm — density, viscosity, specific heat, thermal conductivity and vapour pressure, all at the same state.

Learning zone

Water's specific heat is extraordinary: raising one kilogram by one kelvin costs about 4181 joules, four times the figure for air and nine times that for copper. Hydrogen bonding is responsible: much of the added energy goes into breaking and reforming the bond network rather than into faster motion. That anomaly is why oceans buffer the climate, why a coolant loop the size of a garden hose can carry a megawatt, and why the hydronic rule of thumb 500 × gpm × ΔT gives BTU/h.

It varies less than you would expect, dipping to a shallow minimum of 4179 J/(kg·K) near 36 °C and rising to 4216 at 100 °C, so a single value is usually good to half a percent across the useful range. The historical calorie was defined to make this number exactly 4184 J/(kg·K), one calorie per gram per degree, which is why 4184 and 4186 both circulate: they correspond to water at 20 °C and at 15 °C respectively.

Used by 4 solvers

Cooling Tower Heat Rejection

Q = 500 \, R \, \Delta T

Glycol Loop Heat Transfer (Capacity Derate)

\dot{Q} = \rho c \dot{V} \, \Delta T

Hydronic Heat Transfer (Water)

\dot{Q} = \rho_w c_w \dot{V} \, \Delta T

Sensible Heat (Q = mcΔT)

Q = m c \Delta T

Revised 1 November 2026

Cite this page

formula.expert. (2026, November 1). Specific heat capacity of liquid water. https://formula.expert/constants/specific-heat-water