How this calculator works
For modest temperature changes, expansion is proportional to original size, temperature change and a material coefficient. Use a linear coefficient for length and a volumetric coefficient for volume. The coefficient is assumed constant over the interval. Temperature inputs use absolute scales, while their difference is computed in kelvins, avoiding offset errors when switching Celsius or Fahrenheit.
Formula
L_f = L_0(1 + alpha deltaT); V_f = V_0(1 + beta deltaT). For an isotropic solid at small strain, beta is approximately 3 alpha.
Worked example
A 2 m bar with alpha = 0.00001/K warming by 100 K grows by 0.002 m to 2.002 m. A 1 m³ volume with beta = 0.0003/K warming by 50 K grows by 0.015 m³.
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Frequently asked questions
Can the coefficient be negative?
Yes. Some materials contract on heating over particular temperature ranges.
Can I use a linear coefficient for volume?
Use a volumetric coefficient. For an isotropic solid and small strains it is approximately three times the linear coefficient.
Does this work across a phase change?
No. A phase transition can change density discontinuously and needs an appropriate material model.