Buying the same quantities every day costs you thousands in waste and lost sales. Most restaurants purchase based on averages, creating surplus on quiet days and shortages during busy periods. Matching your purchases to expected guest counts prevents waste and boosts cashflow.
Why daily forecasts save you money
Most restaurants purchase based on gut feeling. Monday the same as Friday. That creates two expensive problems:
- Surplus on quiet days: You buy for 100 covers, 60 show up
- Shortage on busy days: You buy for 100 covers, 140 show up
- Waste: Fresh product that doesn't sell gets thrown away
- Lost sales: Too little product means sold-out dishes
💡 Example:
Restaurant with average 80 covers per day:
- Monday: 50 covers (37% less)
- Friday: 120 covers (50% more)
- Standard purchase: for 80 covers
Result: Monday 30 portions wasted, Friday 40 portions short.
The savings calculation step by step
To calculate savings, you'll compare two scenarios: purchasing based on averages versus purchasing based on forecasts.
Scenario 1: Standard purchasing (without forecast)
You buy every day for your weekly average. That creates structural surplus on quiet days and shortage on busy days.
Scenario 2: Forecast-based purchasing
You adjust your purchases based on expected guests. Less on quiet days, more on busy days.
💡 Calculation example:
Steak (cost price €12, selling price €32):
- Monday without forecast: 30 portions left over = €360 waste
- Monday with forecast: 5 portions left over = €60 waste
- Savings per Monday: €300
Per year (52 Mondays): €15,600 savings
Formula for total annual savings
The formula to calculate your total savings:
Annual savings = (Waste without forecast - Waste with forecast) × 52 weeks
Plus:
Extra revenue = Lost sales without forecast × Number of weeks × Gross margin
⚠️ Note:
Only count waste from perishable products. Frozen products you can carry over to the next day.
Data you need
For an accurate calculation, gather this data over at least 8 weeks:
- Daily covers: Number of guests per day
- Daily purchases: What you bought per product
- Waste per day: What was thrown away
- Sold-out dishes: Times you ran short
- Cost price per product: What each ingredient costs
This data collection phase - the kind of thing you only learn after closing your first month at a loss - reveals patterns you never noticed before. But tracking pays off.
💡 Practical example:
Restaurant tracking over 2 months:
- Average waste: €180/week
- Lost revenue from shortages: €320/week
- With forecast: waste €50/week, no shortages
Savings: (€180 - €50) + €320 = €450/week = €23,400/year
Which products save the most
Focus your forecast purchasing on products with the biggest impact:
- Fresh fish: High cost, short shelf life
- Premium meat: Expensive, limited shelf life
- Fresh vegetables: Quick spoilage, needed daily
- Dairy: Limited shelf life
- Bread and pastries: Daily fresh, high waste
Products with low impact: frozen, canned, dry ingredients.
ROI of forecast systems
Investing in better forecasts costs time and possibly software, but pays back quickly:
💡 ROI example:
Restaurant with €500,000 annual revenue:
Tools like KitchenNmbrs can automate much of this process:
- Current waste: 4% = €20,000/year
- After forecast purchasing: 1.5% = €7,500/year
- Savings: €12,500/year
- System investment: €2,000
Payback period: 2 months
How do you calculate savings? (step by step)
Gather 8 weeks of data
Record daily: number of covers, purchases per product, waste and sold-out dishes. This gives you a reliable pattern of peaks and valleys.
Calculate current waste costs
Add up all discarded products and multiply by cost price. Divide by number of weeks for your average weekly waste.
Calculate lost revenue
Add up all sold-out dishes and multiply by gross margin (selling price minus cost price). This is your lost profit from shortages.
Simulate forecast purchasing
Calculate what you would have bought if you'd known the actual covers. Use a 10% buffer for uncertainty.
Calculate annual savings
Subtract waste with forecast from current waste, add lost revenue and multiply by 52 weeks.
✨ Pro tip
Track your forecast accuracy for 30 days and adjust your safety buffer accordingly - restaurants with 90%+ accuracy can run with just 5% buffer, while those at 70% need 15% to avoid stockouts.
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
How accurate does my visitor forecast need to be?
A forecast that's within 15% of actual numbers 80% of the time already saves significantly. Perfect predictions aren't needed for good results.
Which factors influence my forecast the most?
Day of the week, season, local events, weather and holidays. Start with day patterns, that already gives 60-70% improvement.
What if my forecast is wrong and I have too little?
Keep a 10-15% buffer for uncertainty. Better to have a bit too much than to be sold out. The savings come mainly from avoiding large surpluses.
Can I do this manually or do I need software?
For initial analysis, Excel works. For daily forecast purchasing with multiple products, specialized software becomes more practical and accurate.
How much time does forecast-based purchasing take per day?
After the startup phase: 10-15 minutes extra per day. The time investment pays back through less waste and sold-outs.
Should I adjust forecasts for menu changes or promotions?
Absolutely. New dishes or special promotions can increase demand by 20-40%. Factor these into your forecasts to avoid running short on featured items.
⚠️ EU Regulation 1169/2011 — Allergen Information — https://eur-lex.europa.eu/eli/reg/2011/1169/oj
The allergen information on this page is based on EU Regulation 1169/2011. Recipes and ingredients may vary by supplier. Always verify current allergen information with your supplier and communicate this correctly to your guests. KitchenNmbrs is not liable for allergic reactions.
In the UK, the FSA enforces allergen regulations under the Food Information Regulations 2014.
📚 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
- Warenwetbesluit Bereiding en behandeling van levensmiddelen (2024) — Official source
- WHO — Foodborne diseases estimates (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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