Use this formula: guests × hours × climate factor × hospitality factor = bottles. The climate factor is 0.4 indoors, 0.6 outdoors in mild weather and 1.0 outdoors in heat; the hospitality factor is 1.0 if water is one of several drinks, 1.5 if it's the main drink and 2.0 if guests take bottles to go. A 200-person, 8-hour indoor conference needs about 640 bottles (27 cases).
Key takeaways
- Climate factor: 0.4 indoors, 0.6 outdoors mild, 1.0 outdoors hot.
- Hospitality factor: 1.0 with other drinks, 1.5 water-primary, 2.0 take-home.
- Divide by 24 and round up to get cases.
- Round up to the next price break; extras keep for two years.
- Add unbranded cases for staff and volunteers.
Running out of water at an event is memorable for the wrong reasons. Ordering three times too much is a waste of budget and storage. Here is the formula our account team uses.
The formula
Guests × hours × climate factor × hospitality factor = bottles.
- Climate factor: 0.4 indoors, 0.6 outdoors mild, 1.0 outdoors hot (above 85°F)
- Hospitality factor: 1.0 if water is one of several drinks, 1.5 if water is the main drink, 2.0 if guests take bottles to go
Divide the result by 24 and round up to get cases.
Worked examples
| Event | Math | Bottles | Cases |
|---|---|---|---|
| Indoor conference, 200 people, 8 hrs | 200 × 8 × 0.4 × 1.0 | 640 | 27 |
| Outdoor summer wedding, 150 guests, 5 hrs | 150 × 5 × 1.0 × 1.5 | 1,125 | 47 |
| Golf tournament, 144 players, 5 hrs | 144 × 5 × 1.0 × 1.0 | 720 | 30 |
| Office open house, 80 guests, 3 hrs | 80 × 3 × 0.4 × 1.0 | 96 | 4 (order the 10-case minimum) |
| 5K fun run, 500 runners, 3 hrs | 500 × 3 × 0.6 × 2.0 | 1,800 | 75 |
Round up to the next price break
Per-bottle pricing drops at 480, 960, 1,440 and pallet quantities. If you're close to a break, take it; the extra bottles cost almost nothing and leftovers keep for two years. Check the estimator or read the cost guide.
Mix in blank water
Branded bottles for guests, unbranded cases for crew and volunteers. Same shipment, lower total.
Don't forget the extras
- Speakers, performers and the green room: 4–6 bottles each per day
- Staff and volunteers: 1 bottle per person per hour outdoors
- Welcome bags and gift kits: 1–2 per bag
- A 10% reserve for hot-weather surprises
Tell us your headcount and hours in a quote request and we'll check the math for you.
Frequently asked questions
Indoors with other drinks, about 0.4 bottles per person per hour. Outdoors in heat, about 1 bottle per person per hour, more if water is the main drink.
All of our bottle sizes ship in cases of 24.
For a 4-hour indoor event with other drinks, about 160 bottles, or 7 cases. For a 4-hour outdoor summer event where water is the main drink, about 600 bottles, or 25 cases.
Sealed bottled water keeps for two years, so leftovers can go to your office, the next event or a local charity.
