200ml vs 100ml Reed Diffusers: Which Is Better Value?

Updated 26 October 2026

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Written by IVNA London

A 200ml reed diffuser is usually better value. You pay less per ml, you refill half as often, and the scent holds steady for longer. A 100ml bottle is the better buy for a small loo, for trying a scent you haven't smelled, or for a gift on a tight budget. We only make 200ml, so this guide also tells you when you shouldn't buy ours.

Jump to: How long each size lasts · Why bigger isn't stronger · Price per ml · Cost per week · When to choose 100ml · When to choose 200ml · Quick answers

How long does a 100ml reed diffuser last compared with 200ml?

Most guides put a 100ml bottle at 4 to 8 weeks and a 200ml bottle at 12 to 16 weeks. Others give a 100ml six to ten weeks, and a 200ml three to four months. These are averages, not promises. A radiator, a draught or a full set of fibre reeds can halve them.

The simple rule: with the same fibre reeds in the same room, a 200ml bottle lasts about twice as long. The fibre reeds set how fast the oil leaves. The bottle sets how much oil there is to leave.

	100ml	200ml
Typical lifespan	1 to 2 months	3 to 4 months
Refills a year	6 to 12	3 to 4
Best rooms	Loo, small bathroom, bedside	Hallway, living room, kitchen, landing
Good for testing a new scent	Yes	Less so

Lifespans are guide ranges from published sources, not lab tests. Your room will change them.

Does a 200ml reed diffuser smell stronger?

Not at first. Strength comes from the fragrance, the base liquid and the number of fibre reeds, not the bottle size. A 100ml and a 200ml with the same oil and fibre reeds smell the same on day one.

The difference shows later. Throw drops as the oil level falls, so a smaller bottle starts fading sooner. A 200ml bottle stays near full strength for longer. For more on strength, read strongest reed diffusers UK.

Is a bigger reed diffuser cheaper per ml?

Usually, yes. Most brands charge less per ml for the bigger bottle. At Boots, for example, the AromaWorks 100ml works out at £11.99 per 100ml, and the 200ml at £10.00 per 100ml.

Reed diffuser	Size	Price	Price per 100ml
AromaWorks (Boots, full price)	100ml	£11.99	£11.99
AromaWorks (Boots, full price)	200ml	£19.99	£10.00
IVNA London reed diffuser	200ml	£58	£29.00
IVNA London refill with fresh fibre reeds	200ml	£42	£21.00

We checked prices when we wrote this. Please check each brand's own site.

We are not the cheapest per ml, and we don't pretend to be. What you pay for with us is the blend, the bottle and the time it lasts. That's why cost per week is a fairer test.

How to work out real value: cost per week

Cost per week = price ÷ weeks it lasts in your room

Here's a worked example with a made up 100ml bottle, set against ours:

	Example 100ml	IVNA London 200ml	IVNA London 200ml refill
Price	£30	£58	£42
Weeks it lasts	6	16 (average)	16 (average)
Cost per week	£5.00	about £3.60	about £2.60

The 100ml costs less on the day and more over the year. That gap grows when you refill, because you keep the bottle and only buy the oil and fresh fibre reeds. Read how to refill a reed diffuser.

When a 100ml reed diffuser is the better choice

A small loo or cloakroom. A small room fills easily. A 200ml can be more than you need.
Trying a scent for the first time. If you don't love it, you've spent less.
A gift on a budget. A good 100ml beats a poor 200ml.
Short stays. A holiday let or a room you're about to redecorate.

If any of these fit, a 100ml is the right buy, and we'd rather you bought one than a bottle of ours you don't need.

When a 200ml reed diffuser is the better choice

A room you'll scent all year. Hallways, landings, living rooms, kitchens.
Bigger rooms. More oil feeds a full set of fibre reeds for longer. See our room size guide.
You hate running out. Three or four refills a year, not ten.
A gift that needs to last. It's still going months after the occasion.

Quick answers

How long does a 200ml reed diffuser last?

Usually three to four months. Ours lasts up to 24 weeks, around 16 weeks on average. Less near a radiator.

How long does a 100ml reed diffuser last?

Usually one to two months, depending on the room, the fibre reeds and the heat.

Is it worth buying a bigger reed diffuser?

Yes, if it will stay in one room for three months or more. You pay less per week and refill less often.

Can I use fewer fibre reeds to make a bottle last longer?

Yes. Fewer fibre reeds means a softer scent and a longer life. Read how long do reed diffusers last.

Why we only make 200ml

We chose one size so every bottle lasts a full season. Read the full story in why our reed diffusers come in 200ml. Every IVNA London reed diffuser is handmade in England, with the notes and best rooms listed on each page. When it runs low, a 200ml refill comes with fresh fibre reeds.