How Long Does 1 Litre of Scent Diffuser Oil Last?

A clear way to work out how long a 1 litre bottle of cold-air concentrate lasts in a business or a large home, with worked examples and ways to make it go further.

A litre is the size most businesses and large homes settle on once they know their scent machine. It means fewer reorders and the scent never runs dry on a busy day. But how long does it actually last? Here is how to work it out for your space.

The short answer

In a typical business running a cold-air diffuser during opening hours, 1 litre usually lasts about two to four months. In a large home running mornings and evenings, it can last four to six months or more. A large open space on a high setting, all day, can use it in six to eight weeks.

The range is wide because three things decide it: your machine's output, your hours and your setting.

The formula

Months a litre lasts = 1,000 ml ÷ (ml per hour × hours per day × days per month)

ml per hour: in your machine's manual or app. It changes with the intensity setting. Many units use somewhere around 1 to 3 ml an hour on a working setting.
Hours per day: most businesses scent only while open, on a timer.
Days per month: 26 for six days a week, 30 for every day.

Worked examples

Space	Setting	Use	1 L lasts about
Boutique or salon, 10 h × 26 days	1.5 ml/h	390 ml a month	2.5 months
Office reception, 9 h × 22 days	1 ml/h	198 ml a month	5 months
Hotel-style lobby, 16 h × 30 days	2 ml/h	960 ml a month	1 month
Large home, 6 h × 30 days	1 ml/h	180 ml a month	5.5 months

These are examples. Your machine's real rate may be higher or lower, so check it once and redo the sum.

How to make a litre go further

Run a schedule, not 24 hours. Scent the hours people are there. Nights and closed days are oil wasted.
Use pauses. Most machines mist, then rest. A longer rest at the same intensity often smells just as present and uses far less.
Place the unit where air moves. Near a return vent, an entrance or a corridor, the scent travels on its own.
Turn it down in summer, up in winter. Open doors and air conditioning carry scent away; closed winter rooms hold it.
Keep the bottle closed and out of sunlight between refills, and use a clean funnel.

Why bigger bottles make sense for business

A litre costs less per ml than smaller bottles, and the fewer times you refill, the fewer chances to run out on a Saturday. If you use a litre every month or two, a standing order delivers it on schedule, so nobody has to remember.

Which scent for a litre?

Most businesses choose one signature and stay with it, so guests learn to recognise it.

Thé Blanc: white tea, ginger and soft musk. Clean and calm. Our most requested scent for offices, clinics and salons.
Grand Foyer: bergamot, white jasmine, water lily and soft amber. The classic polished lobby.
Santal Vellum: sandalwood, cardamom, iris and leather. Warm and memorable, for boutiques and lounges.

Not sure yet? In Canada you can try any of our six hotel scents as a 5 ml sample before committing to a litre.

Our concentrates are made for waterless (cold-air, nebulizing) diffusers that have a refillable oil bottle. They are not for water (ultrasonic) diffusers or sealed-cartridge machines.

Quick answers

How long does 1 litre of diffuser oil last? About two to four months in a typical business on a timer, longer in a home, shorter in a large space running all day.

How many ml does a scent machine use per hour? It depends on the model and setting. Many use roughly 1 to 3 ml an hour; check your manual or app.

Is 1 litre cheaper than buying 120 ml bottles? Yes. Larger sizes cost less per ml and mean fewer orders.

Can I split a litre between two machines? Yes, if both are waterless diffusers with refillable bottles. Pour with a clean funnel.

See all Cold-Air Concentrates in 120 ml, 500 ml and 1 L, or tell us about your space and we will suggest the right size and schedule.

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