Specific Heat Calculator

Fill in any three of energy, mass, specific heat, and temperature change, leave the one you want blank, and this page solves for it with the rearranged formula narrated in your own numbers. Pick a material from the list to fill in its measured specific heat, and use the table below to see where your answer sits.

Put this calculator on your website for free

Copy one snippet and give your visitors a working Specific Heat Calculator.

How this specific heat calculator works

Everything on this page is one equation wearing four outfits: q = mcΔT. Fill in any three of the four quantities, leave the one you want blank, and the page rearranges the formula for that variable, substitutes your numbers, and narrates each step so you can follow the algebra rather than trust it. If your unknown is the specific heat itself, the answer comes with company: the result names the material on the reference table it most resembles, because 0.897 J/(g C) means more once you know it is aluminum territory.

Temperature goes in as a change, not a reading. If the water went from 20 C to 30 C, enter 10. A change of zero degrees while energy flows is the one thing this equation cannot describe, and if you ask for it, the page explains why instead of dividing by zero.

The formula

q = m × c × ΔT
c = q ÷ (m × ΔT)
m = q ÷ (c × ΔT)
ΔT = q ÷ (m × c)

q is the heat energy in joules, m the mass in grams, c the specific heat in J/(g C), and ΔT the temperature change in Celsius-sized degrees. Read the first line out loud and it makes sense on its own: the energy needed is how much stuff you have, times how much energy each gram of that stuff wants per degree, times how many degrees you are asking it to climb. The other three lines are the same sentence solved for a different word.

Worked example

Warm 100 g of water by 10 C. Water's specific heat is 4.184 J/(g C), so q = 100 × 4.184 × 10 = 4,184 J, which is 4.184 kJ.

Here is the pleasing part: 4,184 J is exactly 1,000 calories, because the calorie is defined as exactly 4.184 J. And 1,000 calories is one kilocalorie, which is the Calorie on a food label. So warming 100 g of water by 10 degrees costs precisely one dietary Calorie, and a 2,000 Calorie day is the energy to take 20 liters of water from fridge-cold to a rolling boil. Food is fuel in a very literal sense.

Why water's number is the one to remember

Water's 4.184 J/(g C) is not just the anchor of the unit system, it is one of the largest specific heats of any common substance: about 4.7 times aluminum, 9 times iron, and 32 times lead, gram for gram. Hydrogen bonds soak up energy before the temperature responds, and that single number quietly runs a lot of the world you live in.

It is why coastal towns have mild weather: the ocean is a thermal flywheel that absorbs summer and releases it all winter, so San Francisco and Wichita share a latitude and not a climate. It is why radiators and car cooling systems pump water and not oil: each kilogram carries more heat per degree than almost anything cheap and liquid. And it is why your body, which is mostly water, can sit in a 35 C room or a 5 C wind and hold 37 C: you are made of the substance that is hardest to change the temperature of. When something in nature needs temperature stability, water is usually how it gets it.

Why metals feel hot so fast

Flip the same logic over and you get the burned hand on the car door. Metals have tiny specific heats, so the same energy produces far more degrees. The summer sun delivers roughly the same energy to each gram of the door handle and each gram of the lake behind the parking lot, but iron at 0.449 J/(g C) climbs about nine times as many degrees as water does for that energy. The handle is not receiving more heat than the lake. It simply has almost no appetite per degree, so every joule shows up as temperature. That is also why a metal spoon in hot soup is untouchable in seconds while the ceramic mug is merely warm: a small c means a material's temperature is easy to push around, in both directions.

The classic mixing problem: hot metal into cool water

Half the specific heat questions ever assigned are this one: drop something hot into something cool and predict where the temperature settles. The physics is one sentence, heat lost equals heat gained, and the algebra is the equation from this page written twice and set equal.

Drop 100 g of copper at 95 C into 200 g of water at 20 C. The copper's heat capacity is 100 × 0.385 = 38.5 J/C and the water's is 200 × 4.184 = 836.8 J/C. The final temperature is the heat-capacity-weighted average of the two starting temperatures:

Tfinal = (38.5 × 95 + 836.8 × 20) ÷ (38.5 + 836.8) = (3,657.5 + 16,736) ÷ 875.3 = 20,393.5 ÷ 875.3 = 23.30 C

The copper fell 71.7 degrees to lift the water 3.3, a ratio of about 21.7 to 1, which is exactly the ratio of their heat capacities, 836.8 to 38.5. A hand-sized piece of nearly boiling metal barely takes a glass of water off the chill, and that asymmetry is the entire specific heat lesson in one splash. (This assumes no heat escapes to the cup or the air, which is why real measurements run a little low; a good calorimeter earns its keep by making that assumption nearly true.)

Reference table: measured specific heats

Values from the CRC Handbook, quoted near room temperature unless the state says otherwise (ice near 0 C, steam near 100 C, dry air at constant pressure). Click a column heading to sort. Wood and concrete honestly vary from sample to sample: wood runs about 1.2 to 2.3 J/(g C) by species and moisture, so treat the 1.7 as a typical value rather than a constant of nature.

Materialc in J/(g C)c in cal/(g C)
Water (liquid)4.1841.000
Ethanol2.440.583
Ice2.090.500
Steam2.00.478
Olive oil1.970.471
Wood (typical)1.70.406
Dry air1.0050.240
Aluminum0.8970.214
Concrete0.880.210
Granite0.790.189
Iron0.4490.107
Copper0.3850.092
Lead0.1290.031
Gold0.1290.031

Two things worth noticing while you scroll. Liquid water tops the table, and it is not close. And lead and gold tie at the bottom at 0.129 J/(g C), which is why a gold ring in the sun gets uncomfortable so quickly: dense metals with heavy atoms have very few atoms per gram, and it is atoms, not grams, that soak up thermal energy. Notice too that ice and steam are both roughly half of liquid water: same molecule, different arrangement, half the appetite. The 4.184 belongs to liquid water specifically, not to H2O in general.

Celsius, kelvin, Fahrenheit: what a temperature difference cares about

A temperature difference is the same number in Celsius and kelvin, so no conversion is ever needed between them here. The two scales use the same size degree and differ only in where zero sits, and subtracting two temperatures cancels the offset exactly: 30 C minus 20 C is 10, and the same two temperatures in kelvin, 303.15 minus 293.15, is the same 10. This calculator treats the two options as one, and tells you so in the steps, because knowing why you did not convert is worth as much as a conversion.

Fahrenheit is the honest exception. Its degrees are genuinely smaller, 5/9 the size of a Celsius degree, so a Fahrenheit difference converts by that factor alone: an 18 F rise is a 10 C rise. The famous 32 never appears, because the offset cancels in a difference exactly as it does between Celsius and kelvin. If you have ever wondered when temperature conversion gets to skip the 32, this is the place.

Specific heat or enthalpy: which page do you need

This page and our enthalpy calculator are a deliberate pair, and the split is clean. Specific heat answers how much energy does it take to warm this stuff: it is a property of a material, measured in J/(g C), the same for a teaspoon of copper as for a cathedral bell. Enthalpy answers how much heat did this reaction move, per mole: it is a property of a change, measured in kJ/mol, with a sign that carries the direction. The calorimetry experiment is the bridge between them: you measure q with this page's equation, then the enthalpy page divides by the moles that reacted and handles the sign that students lose the most points to.

Nearby tools: our BTU calculator applies this same physics to sizing heating and cooling for a room, our density calculator handles the other everyday property of a material, and our temperature converter is the right tool when you need to convert a temperature reading rather than a difference.

Sources

Where the numbers on this page come from. We go to the body that publishes the figure, not to another calculator. See how we verify.

Frequently asked questions

How do you calculate specific heat?

Divide the heat energy by the mass times the temperature change: c = q / (m times the temperature change). If 1,000 J warms 250 g of metal by 4.5 degrees Celsius, its specific heat is 1000 / (250 x 4.5) = 0.889 J/(g C), which is right in aluminum territory. This page does that division for you and narrates each step, and it can also run the equation the other three ways.

What is the specific heat of water and why is it special?

Liquid water is 4.184 J/(g C), which is enormous: about 4.7 times aluminum, 9 times iron, and 32 times lead, gram for gram. Hydrogen bonding gives water a huge appetite for energy before its temperature responds, and that one number shapes coastal climates, makes water the working fluid in radiators, and is why your mostly-water body holds its temperature so steadily.

Do I use Celsius or kelvin for the temperature change?

Either, and you do not need to convert, because a temperature difference is the same number on both scales. A Celsius degree and a kelvin are the same size; the scales only differ by where zero sits, and subtracting two temperatures cancels that offset completely. Fahrenheit is the exception: its degrees are smaller, so a Fahrenheit difference must be multiplied by exactly 5/9 first.

What is the difference between heat capacity and specific heat?

The mass. Heat capacity is the energy to warm a particular object by one degree, in J/C, and doubles when the object doubles. Specific heat is the energy to warm one gram of a material by one degree, in J/(g C), and stays the same however much of the material you have. Specific heat describes the stuff; heat capacity describes your particular lump of it. Multiply specific heat by mass and you get heat capacity.

Why do metals heat up so fast?

Because their specific heats are tiny, the same energy produces a much bigger temperature rise. Sunshine delivers roughly the same energy per gram to a car door handle and to the lake behind it, but iron at 0.449 J/(g C) climbs about nine times as many degrees as water at 4.184 for that energy. The metal is not receiving more heat; it just has less appetite per degree.

What units is specific heat measured in?

J/(g C) is the everyday unit, and J/(kg K) is the strict SI one; divide J/(kg K) by 1,000 to get J/(g C). A handy identity: kJ/(kg K) and J/(g K) are exactly the same number, so water is 4.184 in both. The older unit cal/(g C) converts by exactly 4.184 J per calorie, which makes water exactly 1 cal/(g C), and that is no accident: the calorie was originally defined as the energy to warm one gram of water by one degree.

Is a calorie the same as the Calorie on a food label?

No, and the capital letter is doing a lot of quiet work. The food label Calorie is a kilocalorie, 1,000 of the small calories this page uses, or 4,184 J. Warming 100 g of water by 10 degrees Celsius takes exactly one food Calorie, which is a nice way to feel how much energy a 2,000 Calorie day actually is.

Related calculators