Use this chemistry calculator to reproduce a named relationship with explicit quantities and units for study, laboratory planning, or an independent numerical check.

Atomic mass (u)

Required number input.

Mass number

Required integer input.

Calculate the conventional nuclear packing fraction from isotopic atomic mass and mass number, reported in parts per ten thousand. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Packing fraction (10^-4)

The resulting packing fraction returned as a number.

• Crystallographic calculations assume the stated ideal lattice, indexing, wavelength, occupancy, and unit-cell geometry. Defects, strain, texture, thermal expansion, mixed phases, and instrumental corrections are outside the compact model.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check units and significant figures, compare the result with limiting cases, and use measured or source-specific constants where available. Laboratory, safety, and regulatory decisions require validated methods and appropriate uncertainty analysis.

• PPM to Mass Percent Converter

  Convert parts-per-million into mass percent by dividing by ten thousand.

• Packing Fraction Calculator

  Calculate the hard-sphere packing fraction of a unit cell from atomic radius, atom count, and unit-cell volume.

• Mass Fraction to PPM Converter

  Convert a mass fraction between zero and one into parts per million by multiplying by one million.