What bulk modulus measures
Bulk modulus (K) quantifies a material’s resistance to uniform compression — how much its volume changes under an applied pressure. It is defined as K = -ΔP / (ΔV / V0), where ΔP is the change in pressure, V0 is the original volume, and ΔV is the resulting change in volume. The negative sign reflects that volume decreases as pressure increases.
How this calculator works
Enter the applied pressure change, the object’s original volume, and the resulting change in volume. The calculator computes the volumetric strain (ΔV / V0) and then divides the pressure change by that strain (with the sign flipped) to get the bulk modulus, shown in both pascals and gigapascals.
A higher bulk modulus means a stiffer, less compressible material — steel and diamond have very high bulk moduli, while gases and rubber have low ones. This calculator is for general engineering and educational purposes.