dilution factor
/ dy-LOO-shun FAK-tor /
When you water down a strong cordial, you can ask 'how many times weaker is it now?' The dilution factor is the number that answers that question — a tidy multiplier telling you how much the original was thinned.
The dilution factor is the ratio of the final total volume to the volume of the original sample taken, or equivalently the factor by which the concentration was reduced. A dilution factor of 10 means the final solution is one tenth as concentrated as the starting one.
It is the lever that lets you go back and forth: multiply a measured diluted concentration by the dilution factor to recover the original, undiluted value. In a serial dilution the overall factor is just the product of the individual steps, which is why small steps can reach large dilutions.
Taking 1 mL of sample and adding solvent to a final 50 mL gives a dilution factor of 50; if the diluted solution reads 4 mg/L, the original held 4 × 50 = 200 mg/L.
Multiply the diluted result by the dilution factor to recover the original.
Beware of '1:10' notation: some people mean one part sample to ten parts solvent (factor 11), others one part in ten total (factor 10). State the convention to avoid an off-by-one error.