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Measurement at home

What is the difference between heat and temperature?

How does your object’s heat compare with that of NPL’s hottest pudding?

  • NPL heated a ‘Christmas pudding’ (made from carbon) to 2,200 ºC.
    Read about the experiment.
  • You may be surprised how our pudding’s heat compares to that of a snowman, a cooked turkey and a candle flame.​
  • What information do you need to calculate the heat of an object?


Estimated time: 20 minutes. No prior knowledge needed.

Download the worksheet

Equipment required​

  • optional thermometer
  • optional weighing scales
  • paper and pencil for calculations.


  • take care when handling hot, cold or heavy objects.

Step by step

Watch the video, then follow the instructions.

  1. Choose an object. At the time of writing it’s Christmas so ours are seasonal. It’s best if your object is made of just one material (like iron or water), though you can simplify (e.g. a person = 100% water).​

  2. Measure or estimate the mass (in kg) and temperature of your object. Convert °C temperature value to K (kelvin) by adding 273.​

  3. Find your material’s ‘specific heat capacity’ value. As living things are mostly water, for them, you could use the value for water = 4,200 J/kg/K. ( (​

  4. Calculate the heat (total thermal energy) of your object​

    = mass (in kilogram) x temperature (in kelvin) x specific heat capacity.​
    There are examples in the downloadable worksheet.

  5. Repeat for other objects and share your results with us, or compare them with our festive object heat vs temperature plot below.

Temperauture vs heat


Thoughts, tips and information

SI measurement units​

  • kelvin (K) for temperature
  • kilogram (kg) for mass.

Challenge topics​

Measurement science, maths, specific heat capacity.

Temperature measures hotness/coldness of a body while heat is a type of energy.​

We calculate heat (thermal energy, unit joule (J)) transferred to change an object’s temperature. Temperature change depends on the object’s mass and a property called ‘specific heat capacity’.

Enter your results

Please enter your results in the table below. You may enter as many results as you like THOUGH PLEASE REFRESH THIS PAGE BEFORE EACH NEW ENTRY. Each time you Submit, you will send us the information written in the cells below.

E.g. Snowman
E.g. 60
E.g. -5
E.g. 268
E.g. 2090
E.g. 34,000,000
* These are optional – the name is so we could mention you in the end of week report and the postcode is to see where people are taking part. We won’t use this information for anything else.