How Long Does 500 ml of Scent Diffuser Oil Last?

How long a 500 ml bottle of cold-air concentrate lasts in a home, an office or a shop, and how to tell whether you should size up to a litre.

500 ml is the middle size: big enough that you are not reordering every few weeks, small enough to try a new scent without committing to a litre. Here is how long it lasts and when to size up.

The short answer

In a home scent machine on a sensible schedule, 500 ml usually lasts about three to five months. In a small business running during opening hours, about one to two and a half months. Run all day in a large space, it can go in three to five weeks.

Work it out for your space

Months it lasts = 500 ml ÷ (ml per hour × hours per day × days per month)

Your machine's ml per hour is in its manual or app and changes with the setting. Many units use around 1 to 3 ml an hour.

Examples

Home, 4 hours a day, 1 ml an hour: 120 ml a month, so 500 ml lasts about four months.
Small office, 9 hours a day, 22 days, 1 ml an hour: about 200 ml a month, so two and a half months.
Busy salon, 10 hours, 26 days, 1.5 ml an hour: about 390 ml a month, so just over five weeks.

When to size up to a litre

Move to 1 litre if any of these are true:

You finish a 500 ml bottle in under two months.
You run a business and running out mid-week would be noticed.
You have settled on one signature scent.

A litre costs less per ml and halves the number of orders.

When 500 ml is the right size

You are still choosing your signature scent and want to rotate.
You scent a home or a single room.
You run two scents in two areas and want both fresh.

Make it last longer

Scent only the hours people are there.
Lengthen the pause between mists before you lower the intensity.
Place the unit where air moves, near an entrance or vent.
Keep the bottle tightly closed and out of the sun.

Popular 500 ml choices

Thé Blanc for a clean, calm space, Grand Foyer for a classic lobby feel, Cèdre Noir for warm wood and leather, and Velours Rose for a softer floral welcome. In Canada, try any hotel scent first as a 5 ml sample.

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 500 ml of diffuser oil last? About three to five months at home on a schedule, one to two and a half months in a small business.

Should I buy 500 ml or 1 litre? If you finish 500 ml in under two months, or you run a business with one signature scent, the litre is better value.

Does diffuser oil go off once opened? Kept closed and away from heat and sunlight, it stays good for a long time. See shelf life and storage.

Shop Cold-Air Concentrates in 120 ml, 500 ml and 1 L.

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