How this calculation works
This first-order model treats the coefficient of linear expansion as constant. Positive temperature changes expand a material with a positive coefficient; negative changes contract it.
Length change = original length × coefficient × temperature changeA worked example
A 1 m sample with coefficient 0.000012/K heated by 100 K lengthens by 0.0012 m.
Good to know
Small-change approximation for free expansion. Does not evaluate thermal stress, constraints or changing material properties.
Small changes can accumulate over a long length
The same expansion coefficient and temperature change produce ten times the length change in a 10 m sample as in a 1 m sample. A small fractional change can therefore become a noticeable dimensional change over a long span.
The coefficient is per kelvin of temperature change. If a reference gives it in “micro per kelvin,” convert the multiplier: 12 micro/K means 0.000012/K.
Free expansion and constrained stress are different problems
This formula estimates how a freely expanding length changes. If an object is restrained, the interaction can create stress instead of allowing that full movement. The tool has no stiffness, constraint or stress model.
It also treats the coefficient as constant and the change as small enough for a linear approximation. Large temperature ranges, changing phases and material-specific behavior require more detailed data.
A few questions, answered
Is this an area or volume expansion?
No. It is a linear length-change model. Area and volume need their own treatment.
Can I use a negative temperature change?
Yes, within the model’s useful range. A positive coefficient then predicts contraction.