A hotel or resort's monthly drinking water cost comes from a simple formula: occupied rooms, times bottles per room per day, times 30 days, times the price per bottle, plus the water your staff drink. That figure is not the real cost. It leaves out delivery, storage space, staff time and plastic waste, which on islands such as Koh Samui and Koh Phangan add more than most managers expect.
This guide walks through the calculation step by step, with a worked example for a 40-room resort and the hidden costs that rarely reach the accounts.
How do you calculate a hotel's drinking water cost per month?
Start from four figures that accounts and housekeeping already hold.
- Average occupancy. Use the real figure for each month, because high and low season differ widely.
- Bottles per room per day. Count the bottles in the room and those served at the restaurant, the pool, the spa and in the shuttle.
- Price per bottle. Use the price you actually pay, delivery included, not the shelf price.
- Number of staff. Staff drinking water is the line most often forgotten.
Multiply these and you have the basic monthly cost. Work it out by season: a full month can use several times the water of a quiet one.
A worked example: a 40-room resort.
Take a 40-room resort with 75% average occupancy, two bottles placed in each room per day and one more per room used at the restaurant and the pool.
| Item | Per day | Per month (30 days) |
|---|---|---|
| Occupied rooms | 30 rooms | 900 room nights |
| In-room bottles (2 per room) | 60 bottles | 1,800 bottles |
| Restaurant and pool bottles (1 per room) | 30 bottles | 900 bottles |
| Total for guests | 90 bottles | 2,700 bottles |
Multiply 2,700 bottles by the price the resort pays and you have the guest side of the monthly bill. These figures are assumptions: replace them with your own, or use our bottled water calculator to see the bottles and litres your site uses in a year.
What hidden costs does the bottle price leave out?
The bottle price is only the visible part. The rest sits in the daily work of the team.
- Delivery. On an island every litre arrives by boat and truck. When the ferry stops for rough seas, stock runs short.
- Storage. Hundreds of crates take storeroom space that could be used for something else.
- Staff time. Receiving, carrying, stocking rooms and chilling, every day.
- Plastic waste. Empty bottles have to be sorted, stored and shipped off the island, at a cost to the resort and to the community.
- Price and stock swings. Bottled water prices and availability move with the tourist season.
Add these lines and the real drinking water cost of a hotel sits above the supplier's invoice, especially on an island.
Should staff drinking water be counted?
Yes. One person drinking two litres a day from half-litre bottles uses 1,460 bottles a year. A team of 50 uses about 73,000. Small bottles or 19-litre jars, every one has to be ordered, delivered, stored and dealt with after use.
Staff water is also a matter of working conditions. A cold water point that works through every shift helps the team drink enough in the heat, with no wait for the next jar.
How does making water on site change the cost?
When a hotel makes its own drinking water, the cost stops growing with every bottle and becomes a fixed, predictable line. No delivery trucks, no crates in the storeroom, no plastic left behind. Guests get mineral-enriched drinking water in glass bottles refilled every day.
Minairal has two ranges. Air atmospheric water generators turn the humidity in the air into drinking water with no water line, which suits villas and resorts with an unreliable supply. Pure systems connect to the existing line where tap water is available. If you are weighing the two, read our comparison of air-to-water, reverse osmosis and bottled water.
Business pricing depends on the points of use and the volume needed, so it follows a site assessment, with a maintenance plan carried out entirely by Minairal technicians.
Can you try it before deciding?
See the systems and taste the water at a Minairal shop or service centre in Koh Samui, Phuket, Hua Hin or our Minairal point in Koh Phangan.
Or try one free for one week at your property in Koh Samui, Koh Phangan, Phuket, Hua Hin or Bangkok. Place it where guests or staff actually drink, and watch how many crates you stop ordering.
Frequently asked questions.
How much drinking water does a hotel use per day?
It depends on the guests and staff on site each day. Two litres per person per day is a sound starting point, adjusted for points of use such as the restaurant, the pool and the gym.
How much water does an atmospheric water generator produce?
Air Top produces 13 L a day on average, Air Stand 16 L and Air Stand Pro 22 L. These are averages for relative humidity between 30% and 80% and an average temperature of 25°C.
What does a Minairal system cost for a hotel?
Business pricing depends on the size and the number of points of use. We quote after a site assessment, so the figure matches how your property actually uses water.
Want to see how much drinking water cost and plastic your property could cut? Ask for a free one-week trial. The Minairal team replies within 4 hours on average during business hours.
