120 ml, 500 ml or 1 L: Which Size of Fragrance Oil Should You Buy for Your Scent Machine?

A simple way to choose the right bottle size for a home scent machine, so you are never running out of your favourite scent or paying for oil that sits on a shelf.

Buying fragrance oil for a scent machine feels simple until you see three sizes side by side. Buy too little and you run out on a Sunday night with guests coming. Buy too much of a scent you have not lived with yet and it sits in a cupboard. The right size depends on three things: how big your machine is, how long it runs each day, and how sure you are about the scent.

Start with what your machine actually uses

Every nebulizing (waterless) diffuser is different. A compact home unit on a gentle schedule uses a small amount each day. A larger machine connected to a whole floor, or one running from morning to night, can use several times more.

The easiest way to know your own rate is to measure it:

Fill the reservoir and note the level with a small piece of tape on the bottle.
Run your usual schedule for seven days, without changing the intensity.
Check how much has gone. Multiply by four and you have a reliable monthly figure for your home.

Once you know that number, choosing a size is easy.

120 ml: for discovering a scent

A 120 ml bottle is the right place to begin when you are trying a scent for the first time, or when your machine is small and runs only in the evening. It lets you live with a fragrance through different times of day and different moods before you commit.

Machines that take 120 ml or 200 ml. Many scent machines draw from their own bottle or reservoir, some sized for 120 ml and some for 200 ml. Either way, 120 ml is a good first fill: pour it into your machine's bottle and top up with the same scent when you are ready.

It is also the size we suggest for second and third scents, the ones you bring out for a season or a dinner party rather than every day.

Explore the collection: Grand Foyer, Thé Blanc, Santal Vellum, Ambre Safran, Cèdre Noir and Velours Rose.

500 ml: for your signature scent

Once a scent has become the scent of your home, the one guests mention when they walk in, 500 ml is the natural next step. Most households running a machine daily find it is the size that lasts long enough to feel effortless, without the bottle lingering for too long after opening.

It is also the size people choose when the machine runs in a busy space: an open-plan main floor, a large entry, or a home office where you spend the whole day.

1 L: for large homes and businesses

A litre makes sense when your machine scents a large home or more than one floor, when it runs most of the day, or when it is working in a business: a salon, a boutique, a studio or a lobby. For larger spaces with several machines, our trade programme offers access by approval.

A quick way to decide

New to the scent, or a small machine: 120 ml, for machines that take a 120 ml or 200 ml bottle.
You already love it and run it daily: 500 ml.
Large home, several floors or a business: 1 L.
Not sure which scent yet: start with The Complete Hotel Edit, all six scents as 5 ml samples, and run each one in your own machine first.

How to keep a larger bottle at its best

Fragrance oil is happiest kept cool, dark and tightly closed. Our concentrates are selected for scent machines and bottled in amber glass in Toronto for exactly that reason: amber glass shields the oil from light. Keep the cap firmly on, store it away from radiators and sunny windowsills, and pour carefully into a clean reservoir. For the truest scent, we suggest using an opened bottle within about a year.

Quick answers

How long does 500 ml of diffuser oil last? It depends entirely on your machine and schedule. Measure one week of use with the tape method above, then divide 500 by your weekly figure to see how many weeks you will get.

Is a bigger bottle better value? Usually yes, per millilitre, but only if you will use it while it is at its best. Buy large for the scent you already love, small for the ones you are exploring.

Can I put reed diffuser refill in my scent machine? No. Reed refills are made to travel up reeds and are the wrong consistency for a machine. More in Why Diffuser Oil Clogs Scent Machines.

Do you ship larger bottles across Canada? Yes, from Toronto, and to the United States.

Our signature scent: Thé Blanc, white tea, ginger and soft musk. It is the scent most guests ask about first, and the one we suggest when you are not sure where to begin.

Explore: the Scaldera Arch · Shop the collection · Take the Scent Quiz · Membership · Refill subscription