Different labels can describe the same dimension with different scales. A fair comparison converts every quantity to one stable base unit, then divides price by that base quantity. Conversion factors are fixed by the product contract and dimensions must remain compatible.
Choose one base for each dimension
Weight can normalize to kilograms, volume to litres, length to metres, area to square metres, and count to items. This contract uses 0.45359237 kilogram per pound and 0.0295735295625 litre per US fluid ounce. Convert quantity before unit price.
Area needs squared conversion factors
Linear and area units are not interchangeable. One inch is 0.0254 metre, but one square inch is 0.00064516 square metre. Flooring, fabric, paper, and coverings must use the area printed on the package, not a single edge length.
Do not invent missing equivalence
A kilogram of one product does not imply a litre, and a roll count does not imply a paper area. Density, thickness, ply, concentration, and quality can make superficially similar packages materially different. Compare only the measurable claim you intentionally selected and assess quality separately.