The labels on a fragrance bottle promise more precision than they deliver. "Eau de parfum" sounds like a fixed specification, and many people assume it is a guarantee of strength. In practice the concentration terms are loose conventions that vary from house to house, and they say much less about how a fragrance will perform than the materials inside it. This guide sets out what the terms mean, defines the vocabulary used to describe performance, explains what actually governs it, and describes how the ratings on this site are meant to be read.
What the concentration labels mean
A fragrance is a solution of aromatic materials, the "concentrate" or "juice", in a carrier, usually ethanol with a little water. The concentration term describes, roughly, what proportion of the bottle is concentrate. The ranges below are the ones most often quoted; note how much they overlap.
- Eau de cologne (EDC): about 2–5% concentrate. Historically a specific citrus-and-herb style from Cologne, now also used loosely for any light splash.
- Eau de toilette (EDT): about 5–15%.
- Eau de parfum (EDP): about 15–20%.
- Parfum, or extrait de parfum: about 20–30%, occasionally higher. Also called "pure perfume" or, in older French usage, simply "extrait".
Three things complicate this tidy ladder.
First, houses vary. There is no regulator enforcing these bands. One brand's eau de toilette may be more concentrated than another's eau de parfum, and some houses apply the terms for reasons of tradition or positioning rather than chemistry. Chanel N°5 exists as parfum, eau de parfum and eau de toilette, and the three are not simply dilutions of one another; each has been reformulated to suit its concentration. Shalimar is similar. When a fragrance appears in more than one strength, treat them as related compositions rather than as the same thing at different volumes.
Second, concentration is not the same as strength. A higher percentage of concentrate means more aromatic material per spray, but the materials themselves determine how loud and how lasting they are. Ten per cent of a heavy, tenacious blend will outlast twenty per cent of a light, volatile one. An EDT can outlast an EDP, and often does: Terre d'Hermès is an eau de toilette that persists for the better part of a day, because its base rests on vetiver, cedar and a large dose of Iso E Super, whereas many floral eaux de parfum with a light musk base are gone by mid-afternoon.
Third, extrait is not always the "strongest" in the sense of projecting furthest. Extraits are frequently designed to sit closer to the skin, with a richer, denser and quieter character than the sprayable EDP. Their virtue is depth and duration, not reach.
The vocabulary of performance
Fragrance writing uses four related terms, and they are worth separating.
Longevity is how long a fragrance remains detectable on skin, from application to the point where you can no longer find it. It is the simplest measure and the one most people mean when they ask whether a fragrance "lasts".
Sillage (French for "wake", as in the trail behind a boat) is the scent trail a wearer leaves behind while moving through a space. A fragrance with strong sillage announces you before you arrive and lingers after you leave.
Projection is how far from the skin a fragrance can be smelled at any given moment while the wearer is stationary. Projection and sillage are closely related, and many writers use them interchangeably, but a fragrance can project strongly for an hour and then collapse, or project modestly and leave a persistent trail. Projection is usually greatest in the first hour and falls as the volatiles evaporate.
Skin scent describes a fragrance, or the late phase of a fragrance, that can be smelled only close to the skin, by the wearer or by someone very near. This is not a failure. Some compositions are designed as skin scents, and almost all fragrances become one in their final hours.
A useful mental picture: longevity is the length of the performance, projection is its volume at any instant, and sillage is the volume as heard by the people you pass.
What affects performance
The concentration on the label is only one of several variables, and rarely the most important.
The materials
This is the dominant factor. Every aromatic molecule has its own rate of evaporation, and a fragrance built mostly from slow-evaporating materials will last longer than one built from fast ones, regardless of concentration. The heavyweights are musk, the amber accord, resins such as benzoin and labdanum, vanilla, patchouli, sandalwood and the synthetic woody-ambers grouped under ambergris (ambroxan, amberwood and related materials). The lightweights are citrus oils, bergamot, lemon, grapefruit, and many green and aromatic notes. This is why a citrus such as Eau Sauvage is short-lived by design, while an amber such as Shalimar or a woody-amber such as Baccarat Rouge 540 can be found on a scarf a week later. Our guide to reading a note pyramid explains the chemistry of volatility in more detail.
Skin
Skin is not a neutral surface. Its temperature, oiliness, pH and hydration all change the rate at which a fragrance evaporates and, to a degree, how it smells. Warm, well-hydrated, slightly oily skin tends to hold fragrance longest; dry skin lets it evaporate quickly. This is the reason two people can wear the same fragrance and report entirely different longevity, and the reason a light, unscented moisturiser applied before spraying often improves duration. Diet, medication and hormones play smaller, less predictable roles.
Weather and setting
Heat accelerates evaporation. In hot weather a fragrance projects more forcefully at first and fades sooner; in cold weather it sits closer and lasts longer. Humidity makes scent seem fuller and heavier. Air conditioning, wind and large open rooms disperse a fragrance so that its sillage seems weaker, while a small, still, warm room concentrates it. A fragrance that feels overpowering in a heated restaurant in January may be almost invisible on a windy beach.
Application
Where and how you apply matters. Pulse points, the wrists, neck and chest, are warm and release fragrance steadily. Fragrance applied to clothing and hair lasts far longer than on skin, because fibres do not absorb or metabolise it, though it will also change less over time and may leave marks on delicate fabric. Rubbing the wrists together after spraying generates heat and friction that hurry the top notes away; it does no lasting harm to the fragrance but removes some of its opening. More sprays give more longevity and more projection, up to a point, but they also make the opening louder for everyone else.
Your own nose
The final variable is olfactory fatigue. After a period of continuous exposure, the nose stops registering a constant smell. Wearers routinely report that a fragrance has "vanished" after two hours while the people around them can still smell it clearly. If you want to judge your own longevity honestly, step outside for a few minutes and come back, or ask someone else.
How to read our ratings
Each fragrance page on this site carries two scores from one to five, one for longevity and one for sillage. They summarise a general consensus among experienced wearers, not laboratory measurements, and they describe the fragrance as most people wear it, on skin, in temperate conditions, with two or three sprays.
Longevity
- 1 — fleeting: an hour or two at most. Classical citrus colognes.
- 2 — short: three to four hours before it becomes faint. Most citrus and green eaux de toilette, such as Eau Sauvage.
- 3 — moderate: five to six hours, a working morning and lunch. Many florals and lighter woods.
- 4 — long: seven to nine hours, a full day at the desk. Well-fixed woods and chypres, such as Mitsouko or Terre d'Hermès.
- 5 — very long: ten hours or more, and still present the next morning. Ambers and woody-ambers, such as Shalimar or Baccarat Rouge 540.
Sillage
- 1 — skin scent: perceptible only to the wearer or someone very close.
- 2 — intimate: noticeable within an arm's length.
- 3 — moderate: fills your immediate personal space; noticed in conversation but not across a room.
- 4 — strong: leaves a clear trail; noticed as you pass. Typical of big ambers and gourmands such as Angel.
- 5 — enormous: fills a room and lingers after you leave. Rare, and rarely desirable in close company.
The two scores are independent. A fragrance can rate 5 for longevity and 2 for sillage, which describes many extraits and most well-made skin scents; it can rate 4 for sillage and 3 for longevity, which describes many fresh fragrances that shout for an hour and then settle. As a rule of thumb from our writing brief, an eau de cologne citrus lands around 2 and 2, and a large amber around 5 and 4.
Remember that these are population averages. Your skin, your climate and your application will shift them by a point in either direction.
Debunking "beast mode"
Online fragrance culture prizes what it calls "beast mode": fragrances that last all day and project across the room. A few claims made in its name deserve scrutiny.
"Stronger is better." Strength is a property, not a virtue. A fragrance that fills a lift is a pleasure to its wearer and an imposition on everyone else. The finest compositions in perfumery, including several of the fifteen catalogued on this site, are not especially loud; Un Jardin sur le Nil is deliberately transparent, and Chanel N°5 in extrait is designed to be discovered rather than announced.
"EDP always beats EDT." As set out above, the label is a weak predictor. Concentration matters less than composition, and houses do not use the terms consistently.
"Longevity claims of twelve hours or more are measured facts." They are almost always self-reports, made under uncontrolled conditions, by people who are highly motivated to notice the fragrance. Olfactory fatigue, fabric contamination (sniffing a cuff rather than skin) and generous application all inflate them.
"If I can't smell it, it's gone." Usually it is not. The fatigue effect means the wearer is the least reliable judge of their own fragrance after the first hour.
"Performance can be fixed by spraying more." More sprays extend longevity modestly and increase projection considerably. The result is not a longer-lasting version of the fragrance you liked at two sprays; it is a louder one, with a heavier opening and, very often, a headache for the person beside you. If a fragrance you love does not last, the honest solutions are to reapply, to spray fabric, or to accept that some beautiful things are brief.
The point of understanding concentration and performance is not to chase the loudest option but to make an informed choice: to know that a citrus will be gone by lunch and to enjoy it anyway, or to know that an amber will still be with you at midnight and to dose it accordingly. Our fragrance pages describe how each composition behaves over time, and the glossary defines every term used here.