Heat Energy Calculator
Calculate signed heat transfer from mass, specific heat and initial/final temperatures. Compare energy units and see a heating or cooling energy chart.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Convert both temperatures to kelvin before subtracting. Multiply mass in kilograms, entered specific heat in J/(kg·K) and the signed temperature difference. A negative result represents heat leaving the material.
Q=mc(T_final−T_initial)
Worked example
Using an entered specific heat of 4184 J/(kg·K), heating 1 kg from 20 °C to 80 °C requires 251040 J = 251.04 kJ. Reversing the temperatures gives −251.04 kJ.
Assumptions and input details
Enter the material’s appropriate specific heat; 4184 is an illustrative entered value, not a lookup or a universal constant for water. Mass and specific heat must be positive. Temperatures may use different scales but cannot fall below absolute zero. The model assumes constant specific heat and excludes phase changes, evaporation, losses, containers, electrical efficiency and heating time. Kelvin and Celsius differences have the same size; Fahrenheit/Rankine differences use 5/9.
References: OpenStax: specific heat and calorimetry
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
The 19 mass definitions distinguish avoirdupois and troy measures, metric and regional measures. Japanese kin is 600 g; mainland Chinese shijin is 500 g.
Regional measures are not interchangeable merely because their names look similar. This is a documented selection, not a claim to include every historical unit.
NIST measurement tables · Japanese traditional units · Mainland China and Hong Kong unit distinctions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
Convert Celsius, Fahrenheit, kelvin and Rankine. Distinguish actual temperatures from temperature changes, and compare all four scales in a table.
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Find density, mass or volume from the other two values. Choose international and regional units and inspect the formula and unit-conversion tables.
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