73% of restaurants underestimate their annual water costs by over €8,000. Water appears insignificant, but mineral water expenses accumulate rapidly across hundreds of daily covers. Understanding the true cost per glass helps you make smarter margin decisions.
Why water costs add up fast
Water might seem trivial, but you're serving glasses with most dishes. With 200 covers daily, that's 73,000 glasses annually. The gap between tap and mineral water can mean thousands in savings – the kind of thing you only learn after closing your first month at a loss.
? Example:
Restaurant with 200 covers/day, 6 days/week:
- Tap water: €0.003 per glass = €234 per year
- Spa blue: €0.18 per glass = €11,232 per year
Difference: €11,000 per year
Calculate tap water costs
Dutch tap water averages €1.50 per 1000 liters. Standard water glasses hold 200ml (0.2 liters).
Formula for tap water per glass:
€1.50 / 1000 × 0.2 = €0.003 per glass
But you'll need to add:
- Glass washing costs (soap, energy): roughly €0.02
- Staff time for pouring: roughly €0.01
Total tap water cost: €0.033 per glass
Calculate mineral water costs
Mineral water gets purchased by the bottle. Figure out how many glasses each bottle yields.
? Example Spa blue:
- Purchase price: €0.90 per 750ml bottle
- Glasses per bottle: 750ml ÷ 200ml = 3.75 glasses
- Cost per glass: €0.90 ÷ 3.75 = €0.24
Plus washing and labor: €0.24 + €0.03 = €0.27 per glass
Compare different water brands
Different brands carry different per-liter costs. Always calculate back to cost per glass for accurate comparison.
? Cost comparison per glass (200ml):
- Tap water: €0.033
- Spa blue (750ml): €0.27
- Evian (500ml, €0.75): €0.33
- San Pellegrino (750ml, €1.20): €0.35
Impact on your food cost percentage
If water comes complimentary with each dish, include these costs in your ingredient calculations for food cost analysis.
⚠️ Note:
If water appears as a separate €2.50 line item on bills, don't include it in food cost calculations. That's a distinct revenue stream.
For a €25 dish (excl. VAT), tap water adds 0.1% to food cost, while premium mineral water can bump it up 1.4%.
Choosing the right option
Your decision depends on concept and pricing strategy:
- Tap water: Casual dining, bistros, daily menus under €20
- Budget mineral water: Mid-range restaurants €20-30, as complimentary service
- Premium water: Fine dining establishments, especially if charged separately
Many restaurants offer both approaches: complimentary tap water, mineral water for an additional charge.
Smart purchasing strategies
For mineral water procurement, consider:
- Price per liter, not per bottle (bottle sizes vary)
- Deposit requirements (Spa has none, many others do)
- Expiration dates (usually long, but verify on delivery)
- Storage requirements (tap water needs zero inventory space)
? Purchasing tip:
Buy mineral water by tray or pallet for better unit prices. A 12-bottle tray of Spa blue often costs €9-10 versus €0.90 per individual bottle.
Related articles
How do you calculate water costs per dish?
Determine your water consumption per guest
Measure how much ml of water you serve by default. Usually this is 200ml for a normal glass. Also note whether you refill and how many glasses per guest on average.
Calculate the cost per glass
For tap water: €1.50 per 1000L ÷ 1000 × 200ml = €0.003. For mineral water: purchase price per bottle ÷ number of glasses from that bottle. Don't forget washing and labor time (approximately €0.03).
Add to your ingredient costs
If you serve water for free, add the costs to your other ingredients for the food cost calculation. If you charge for water separately, calculate the margin on water separately.
✨ Pro tip
Track your actual water usage weekly by counting opened bottles and dividing by guest count. Most restaurants pour 15-20% more water than calculated, especially when staff drinks from service bottles during shifts.
Calculate this yourself?
In the KitchenNmbrs app you can do this in just a few clicks. 7 days free, no credit card.
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Frequently asked questions
Is tap water always cheaper than mineral water?
Should I include water costs in my food cost calculations?
Which mineral water brand offers the optimal margin?
How should I handle deposit costs in my calculations?
Can water function as a profit center?
What's the breakeven point for offering free mineral water?
How do I calculate water costs for dishes with different glass sizes?
Sources consulted
- EU Verordening 852/2004 — Levensmiddelenhygiëne (2004) — Official source
- EU Verordening 853/2004 — Hygiënevoorschriften voor levensmiddelen van dierlijke oorsprong (2004) — Official source
- EU Verordening 1169/2011 — Voedselinformatie aan consumenten (2011) — Official source
- NVWA — Hygiënecode voor de horeca (2024) — Official source
- NVWA — Allergenen in voedsel (2024) — Official source
- Codex Alimentarius — International Food Standards (2024) — Official source
- FSA — Safer food, better business (HACCP) (2024) — Official source
- BVL — Lebensmittelhygiene (HACCP) (2024) — Official source
Food Standards Agency (FSA) — https://www.food.gov.uk
The HACCP standards shown in this application are for informational purposes only. KitchenNmbrs does not guarantee that displayed values are current or complete. Always consult the FSA or your local authority for the latest regulations.
Written by
Jeffrey Smit
Founder & CEO of KitchenNmbrs
Jeffrey Smit built KitchenNmbrs from 8 years of hands-on experience as kitchen manager at 1NUL8 Group in Rotterdam. His mission: give every restaurant owner control over food cost.
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