Specific Heat Calculator

The specific heat formula is one of the most fundamental equations in thermodynamics. It relates the heat energy transferred to or from an object to its mass, its specific heat capacity, and the temperature change it undergoes.

The formula: Q = m × c × ΔT

Where:

• Q = Heat energy transferred (Joules, J or calories, cal)
• m = Mass of the substance (kg or g)
• c = Specific heat capacity (J/kg·°C or J/g·°C)
• ΔT = Temperature change (°C or °F, where ΔF = ΔC × 9/5)

Rearranged to solve for each variable:

• Temperature change: ΔT = Q ÷ (m × c)
• Specific heat: c = Q ÷ (m × ΔT)
• Mass: m = Q ÷ (c × ΔT)

Specific heat capacities of common materials:

Why water has a high specific heat: Water’s specific heat (4.186 J/g·°C) is exceptionally high compared to most substances. It takes a lot of energy to heat water, which is why water is used as a coolant in engines, why coastal areas have milder climates than inland ones, and why the human body (about 60% water) holds a stable temperature despite the heat its own metabolism produces.

Practical example (metric): How much energy is needed to heat 500g of water from 20°C to 100°C? Q = 500 × 4.186 × (100 − 20) = 500 × 4.186 × 80 = 167,440 J (167.4 kJ)

Practical example (imperial): 1 BTU is defined as the heat needed to raise 1 pound of water by 1°F. To heat 2 lbs of water by 50°F: Q = 2 × 1 × 50 = 100 BTU

Unit conversions:

• 1 calorie = 4.184 J
• 1 BTU = 1,055 J = 252.2 calories
• 1 kJ = 1,000 J