basic

Internal Energy Change ΔU Calculator

First law of thermodynamics: ΔU = q + w.

Compute the change in internal energy ΔU of a closed system using the first law of thermodynamics, ΔU = q + w, with the IUPAC sign convention (work done **on** the system is positive).

Dr. Helena Ortiz By Dr. Helena Ortiz
Published Last reviewed 1 min read

Inputs

J
J

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

ΔU = q + w

In depth

Compute the change in internal energy ΔU of a closed system using the first law of thermodynamics, ΔU = q + w, with the IUPAC sign convention (work done **on** the system is positive).