2BHK, four positions: about 1,172ml. Year one ₹10,444; roughly ₹8,200 after.
3BHK with one machine: about 936ml of reed oil plus about ₹999 of Hotel Collection. Year one ₹11,792; roughly ₹7,551 after — less than the 2BHK, with one more room scented.
2. Then apply the ladder, which is the whole price list. Per millilitre, a 50ml at ₹749 is ₹15.00, a 130ml at ₹1,249 is ₹9.60, a 300ml refill at ₹2,399 is ₹8.00 and a 500ml at ₹3,499 is ₹7.00. So a one-bedroom flat needing 468ml a year buys it for about ₹3,700 as 300ml refills or ₹3,499 as a single 500ml — which covers the entire year with 32ml to spare, since 500 − 468 = 32. One order, one year.
3. Budget year one separately, because it is the only year you buy glass. A 1BHK's two bottles — a 130ml at ₹1,249 and a 50ml at ₹749 — is ₹1,998 and supplies 180ml of the 468ml you need. The remaining 288ml is one 300ml refill at ₹2,399. ₹1,998 + ₹2,399 = ₹4,397, or about ₹366 a month. From year two the glass is yours and the same home costs ₹3,499. Nobody tells you the first year is the expensive one, and it is the reason people think the running cost is higher than it is.
4. Expect the machine to reduce the number, not raise it. This is the part that surprises people. A large living room run on six reeds evaporates about 422ml a year — roughly ₹2,950 of oil. Cover that room with a Sukoon instead and it runs on three to six drops a tank, so about ₹999 of a 100ml Hotel Collection covers a year comfortably. The ₹1,899 machine is a one-off that pays for itself inside its second year on that room alone. It does not follow for bedrooms, where a bottle on four reeds costs about ₹1,975 a year and a machine is the wrong tool regardless.
5. And the largest line in the budget is always the positions you decided not to have. Two 50ml positions at three reeds — the classic passage and spare room — are 372ml a year between them, or roughly ₹2,600 of oil you would be buying for a corridor measured in seconds of occupancy and a bedroom used twice a month. Deleting them is free and permanent. No refill discount in the range saves as much as one position you never open.
Made in India, composed by an ISIPCA Versailles-trained perfumer — and a portion of every order supports girl-child education through Nanhi Kali.
Why the annual number is a volume, and not a bill
Most people budget this category by adding up product prices, which produces a figure that is either far too high or far too low and never right. Too high, because they count four bottles as a year when four 130ml bottles is about five months. Too low, because they count the first purchase and forget that a reed diffuser is a consumable that runs whether anybody is home or not. The correct unit is millilitres of oil evaporated per year, because that is the only thing you buy more than once. The glass bottle, the collar and even the reeds are durable — reeds get replaced at refills, and they come with each bottle anyway. Everything else on the invoice is oil, priced four different ways depending on the container you buy it in.
The conversion is one division per room. Bottle life at the reed count you actually run, divided into 52, gives fills per year; multiply by volume. A 130ml runs about sixteen weeks on six reeds, nearer twenty-four on four and around thirty-two on three; a 50ml runs about seven weeks on six and nearer fourteen on three. So a living room on six reeds is 3.25 fills, or 422ml a year. A bedroom on four is 2.17 fills, or 282ml. A bathroom 50ml on three is 3.71 fills, or 186ml. Add the rooms you actually have and you have your figure, and it will be somewhere between about 450ml for a small flat and about 1,200ml for a four-position family home. Then price it on the ladder — ₹15.00 a millilitre in a 50ml, ₹9.60 in a 130ml, ₹8.00 in a 300ml refill, ₹7.00 in a 500ml — and you have an annual budget that will not surprise you in October. The rest of the exercise is deciding which positions deserve to be in the sum at all.
The three decisions that set a year
Your number450–1,200mlLiving room, 130ml, six reeds: 52 ÷ 16 = 3.25 fills = 422ml a year. Bedroom, 130ml, four reeds: 52 ÷ 24 = 2.17 fills = 282ml. Bathroom, 50ml, three reeds: 52 ÷ 14 = 3.71 fills = 186ml. Add the positions you genuinely have. A one-bedroom with a living room on four reeds and one bathroom comes to about 468ml. A two-bedroom with a living room on six, two bedrooms on four and a bathroom comes to about 1,172ml. That single figure is your budget, before a single price has been looked at.Sizing by space — a year, by home
Each row is a whole home for a whole year. Year-one figures include the bottles; the later-year figures are oil only. The last row is what you save by leaving two rooms out.
| Space | What it needs | How many | Cost |
|---|---|---|---|
| 1BHK — living room on four reeds, one bathroom on three ★ | About 468ml of oil a year. Year one: ₹1,998 of bottles + a 300ml refill at ₹2,399. After that, one 500ml refill covers the whole year | Two positions | ₹4,397, then ₹3,499 |
| 2BHK — living room on six reeds, two bedrooms on four, one bathroom on three | About 1,172ml a year. Year one: ₹4,546 of bottles + a 500ml at ₹3,499 and a 300ml at ₹2,399 | Four positions | ₹10,444, then about ₹8,200 |
| 3BHK with a machine in the open living-dining | About 936ml of reed oil plus roughly ₹999 of Hotel Collection — the big room comes off the oil budget entirely | One machine, four bottles | ₹11,792, then about ₹7,551 |
| Any of the above, run on six reeds throughout | Add roughly half again to the oil — 52 ÷ 16 against 52 ÷ 24 is a factor of 1.5 on every position | Same positions | about 50% more |
| One room, one bottle, four reeds | About 282ml a year — the cheapest honest year in the range, and a perfectly good home | One position | about ₹1,975 of oil |
| The passage and the spare room | Nothing. Two 50ml positions at three reeds is 372ml a year — leaving them out saves more than any refill discount in the range | None | ₹0, saving ₹2,600 |
| A note on all of the above: every millilitre figure here is derived from the stated bottle lives — 6–8 weeks for a 50ml and 14–18 for a 130ml on six reeds — with the reed-to-weeks trade treated as roughly proportional. Heat and airflow move real bottle life in both directions, so treat these as the right order of magnitude and your own first year as the measurement that counts. Budget slightly over rather than under: unopened refill carries into next year, whereas a dry bottle does not. | |||
One room · the unitFrom ₹749Shop → 
Two rooms · better value₹1,498Shop → 
Large room · a switch₹1,899Shop →
Three worked budgets, with the totals checked
The one-bedroom flat: two positions, about 468ml a year. A 130ml in the living room on four reeds is 52 ÷ 24 = 2.17 fills, or 282ml. A 50ml in the bathroom on three reeds is 52 ÷ 14 = 3.71 fills, or 186ml. Together 468ml. Year one you must buy glass: a 130ml at ₹1,249 and a 50ml at ₹749 is ₹1,998 and supplies 180ml, leaving 288ml to find, which one 300ml refill at ₹2,399 covers. ₹1,998 + ₹2,399 = ₹4,397, about ₹366 a month. From year two you own the glass, so the whole year is a single 500ml refill at ₹3,499 — 500 − 468 = 32ml spare — which is one order and about ₹292 a month. That is a properly scented one-bedroom flat for less than a coffee a week.
The two-bedroom flat: four positions, about 1,172ml a year. Living room 130ml on six reeds, 422ml. Two bedrooms on four reeds, 282ml each, 564ml. One bathroom 50ml on three reeds, 186ml. Total 1,172ml. Year one buys three 130ml bottles and a 50ml — ₹1,249 + ₹1,249 + ₹1,299 + ₹749 = ₹4,546 — supplying 440ml, and the remaining 732ml is a 500ml at ₹3,499 plus a 300ml at ₹2,399, or ₹5,898. ₹4,546 + ₹5,898 = ₹10,444, about ₹870 a month. From year two it is oil only: 1,172ml at the 500ml rate of ₹7.00 a millilitre is about ₹8,200, or roughly ₹684 a month. Drop the living room to four reeds and the year falls by about 140ml, which is another ₹980 saved for nothing.
The three-bedroom with one machine: the year gets cheaper, not dearer. Put a Sukoon at ₹1,899 in the open living-dining with a 100ml Hotel Collection at ₹999 — ₹2,898 — and reeds in two bedrooms at ₹1,249 and ₹1,299, a bathroom at ₹749 and the entrance at ₹799. Year one hardware and bottles: ₹2,898 + ₹1,249 + ₹1,299 + ₹749 + ₹799 = ₹6,994. The four reed positions drink 282 + 282 + 186 + 186 = 936ml a year; the bottles supply 360ml, and two 300ml refills at ₹2,399 cover the remaining 576ml for ₹4,798. Year one totals ₹11,792. But from year two it is 936ml of oil at ₹7.00 — about ₹6,552 — plus roughly ₹999 of Hotel Collection, or about ₹7,551. That is less than the two-bedroom's ₹8,200 while scenting one room more, because the largest consumer in any home is a big room on six reeds. Do not extend the logic upward: the Megh at ₹3,499 covers about 215 sq ft, less than the Sukoon, and buys runtime rather than area.
What to buy
A year is one purchase of glass and two or three of oil. These are the lines that make up both, with the per-millilitre figure that decides between them.
| Buy | What it covers | Lasts | Price |
|---|---|---|---|
| One 50ml | A single reed diffuser — a bathroom position — 186ml a year on three reeds, but ₹15.00 a millilitre as a way of buying oil | 6–8 weeks | from ₹749 |
| One 130ml ★ | The value size — each main position, bought once — ₹9.60 a millilitre, and the glass is yours from then on | 14–18 weeks | from ₹1,249 |
| The duo | Day & Night duo — opening two positions in a single order, then staggering them so the year spreads evenly | 6–8 weeks each | ₹1,498 |
| Sukoon | 500ml ultrasonic — the one room over about 200 sq ft — it removes roughly 422ml a year from your oil budget | Runs when you switch it on | ₹1,899 |
| 300ml refill | The running cost — every year after the first — ₹8.00 a millilitre, or ₹7.00 if you take the 500ml at ₹3,499 | Roughly 2 × 130ml fills | ₹2,399 |
Versailles
People ask me for an annual figure and I always ask for one number back: how many millilitres does your home evaporate? That is the whole budget. The glass, the collar and the reeds are durable and you buy them once. Everything you spend after that is oil, priced somewhere between ₹7.00 and ₹15.00 a millilitre depending entirely on the container you choose to buy it in.
The thing that catches people out is that year one and year two are different budgets. A one-bedroom flat is ₹4,397 the first year, because ₹1,998 of that is bottles, and ₹3,499 every year afterwards. That step down is real, and not knowing about it is why so many people decide after four months that this is an expensive habit. It is a front-loaded one, which is not the same thing.
And the biggest saving is never a discount. Two positions you decided not to open — the passage and the spare room — are about 372 millilitres a year, or ₹2,600 of oil. That is more than the difference between rebuying bottles and buying the largest refill, across the whole house. I would rather help you spend ₹3,500 a year well than ₹9,000 a year on rooms nobody sits in. A portion of every order funds a girl's classroom through Nanhi Kali.
Frequently asked questions
- A year of four bottles — the annual number, derived.
- Two bottles at half strength — the same weekly cost, two rooms.
- When a 300ml refill starts paying — the crossover, in fills.
- The complete sizing and quantity guide — every home type, three builds.
- Brand: the SOSA founder story.
SOSA products & prices (verified August 2026): Hotel Collection water-based ultrasonic diffuser fragrance 15ml ₹299 · 100ml ₹999 · 300ml ₹1,799 · Pack of 7 (15ml, all fragrances) ₹1,799; refills 100ml from ₹999. Seven scents: The Ritz-Carlton-inspired (white tea · bergamot · cedar), Westin-inspired (white tea · aloe · cedar), 1 Hotels-inspired (cedarwood · vetiver · green leaves), The St. Regis-inspired (amber · violet · woods), Shangri-La-inspired (jasmine · green tea · white tea), Four Seasons-inspired (citrus · floral · sandalwood), W Hotels-inspired (citrus · pepper · amber). Diffusers: Boond 300ml ₹899 · Sukoon 500ml ₹1,899 · Megh 6L ₹3,499. Water-based, phthalate-free, composed to IFRA standards for home diffusion; 3–6 drops per tank. Made in India, Pune. The Hotel Collection scents are SOSA's own interpretations inspired by the world's finest hotels; all hotel names are trademarks of their respective owners and are used only to describe the scent style — SOSA is an independent Indian fragrance house, not affiliated with or endorsed by any hotel brand. Prices and availability subject to change — see the live product pages.