Choose by the Hours You Need

An ordered procedure: list the hours, match the row, read the percentage, expect intensity to track the oil share.

Step 1 — list the hours the scent must last on skin. Two hours covers a short event, 2 to 4 hours covers an afternoon, 6 to 8 hours covers a full evening.

Step 2 — match that number to a row in the concentration table. About 2 hours points to cologne; 2 to 4 hours points to eau de toilette at 5–15%; 6 to 8 hours points to parfum or extrait at 15–30%.

Step 3 — read the percentage on the label. The class name gives the band; an exact printed figure narrows it. Expect intensity to rise with the oil percentage inside the band.

Step 4 — check the failure mode. Judging longevity by the bottle size or the price is the typical mistake: a 100 ml eau de toilette still holds only 5–15% oil, and a small parfum bottle holds 15–30%.

The ordering never reverses. Cologne fades first, eau de toilette next, eau de parfum after that, parfum last — because each step up the scale carries more aromatic compounds.

• 2 hours → cologne
• 2–4 hours → eau de toilette, 5–15%
• 6–8 hours → parfum or extrait, 15–30%
• Failure mode: judging longevity by bottle size or price

Further reading

• Concentration Classes Side by Side
• Milestones in Perfume Making