A formula can be exact for entered numbers while the measurements describe a different physical question. DensityCalc deliberately calculates mass density only and cannot inspect the object or substance behind those values.
Mass and weight are different quantities
Mass is measured in kilograms. Weight is a force that depends on gravitational acceleration and is measured in newtons. Enter a measured mass, not a force reading that has not been converted by the instrument.
Bulk density includes the chosen occupied space
Powders, grains, and porous materials may include voids between particles in the measured volume. Packing, moisture, and procedure can change that result, so the calculator never substitutes a reference value or labels a material.
State temperature and pressure when they matter
Fluid density can vary with temperature and pressure. DensityCalc records neither condition and offers no authoritative material table, so preserve them separately whenever the result supports scientific or engineering work.