Adding an extra shift sounds logical when you're fully booked, but it can also destroy your profit. Most entrepreneurs focus on extra revenue while overlooking the hidden costs that eat away at margins. The reality is more complex than simply opening your doors for additional hours.
The break-even calculation for an extra shift
An extra shift only makes sense if additional revenue exceeds the extra costs. Sounds straightforward, but many restaurant owners underestimate hidden expenses.
💡 Example:
Restaurant considering adding a lunch shift:
- Expected lunch revenue: €800 per day
- Extra staff costs: €320 (2 people x 4 hours x €40/hour)
- Extra food cost: €240 (30% of €800)
- Extra energy/gas: €25
Total extra costs: €585 - Break-even: €585 revenue needed
Which costs do you include?
With additional shifts, you'll face variable costs that scale with revenue and fixed costs that remain constant.
Variable costs per extra shift:
- Staff: Hourly wage plus employer contributions (typically 30-40% on top of gross wage)
- Food cost: 28-35% of additional revenue
- Energy: Extra gas, electricity for kitchen and lighting
- Dishwashing: More dishes means more dishwashing liquid
- Consumables: Napkins, toothpicks, cleaning supplies
Fixed costs remain unchanged:
- Rent, insurance, subscriptions
- Depreciation on equipment
- Basic costs like internet, phone
⚠️ Note:
Always include employer contributions. The gross hourly wage isn't your actual staff cost. Add 30-40% on top for social contributions, holiday pay and pension premiums.
The 70% rule for extra shifts
Here's a useful guideline: extra revenue should be at least 70% higher than variable costs. Why? Fixed costs still need coverage from tracking this across dozens of restaurants.
💡 Example calculation:
Variable costs lunch shift: €585
- Minimum revenue for break-even: €585
- Minimum revenue for profitability: €585 x 1.7 = €995
At €800 expected revenue, you're below the 70% threshold. Risk of operating at a loss.
Making realistic revenue estimates
The toughest question: how much will you actually earn during that extra shift? Many restaurant owners get overly optimistic here.
Check these factors:
- Location: Are there enough people passing by during lunch hours?
- Competition: How many lunch spots already operate in your area?
- Target audience: Are there nearby offices that order lunch regularly?
- Season: Is it a tourist area that gets busy during summer months?
Start conservatively. Calculate using 60% of your optimistic estimate for the first few months.
Testing without big risk
You don't need to commit to a full shift immediately. Test first with limited hours or weekend service.
💡 Smart testing:
- Start with 2 days per week lunch service
- Use existing staff on overtime
- Limited lunch menu requiring less preparation
- Track revenue and costs for 4 weeks
Only expand to full lunch service once the numbers prove profitable.
Digital tools for shift analysis
Tracking costs per shift becomes simpler with digital tools. You can see exactly which shifts generate profit and which don't.
Using a system like tools like KitchenNmbrs lets you track food costs per shift and quickly calculate what an extra shift actually costs. This helps you make data-driven decisions rather than relying on intuition.
How do you calculate whether an extra shift makes sense? (step by step)
Calculate all extra costs
Add up: staff (including employer contributions), food cost (30% of expected revenue), energy, consumables. These are your variable costs per shift.
Estimate realistic revenue
Look at location, competition and target audience. Calculate conservatively: take 60% of your optimistic estimate for the first few months.
Apply the 70% rule
Your revenue must be at least 70% higher than your variable costs. Otherwise you'll run a loss. If in doubt: test first 2 days per week.
✨ Pro tip
Track your current revenue per hour during similar time slots for 3 weeks before making the shift decision. This gives you realistic baseline data rather than optimistic guesses.
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
What if I have existing staff work overtime instead of hiring?
Overtime typically costs 125-150% of the normal hourly wage. Include this premium rate in your calculation, not the regular wage. Don't forget that overtime also increases employer contribution costs.
How do I account for seasonal fluctuations in my calculations?
Calculate separate scenarios for peak and off-season periods. Use your lowest expected revenue figure as the baseline for decision-making. Many restaurants that work during summer struggle during quieter months.
Should I factor in equipment wear from extended operating hours?
Yes, extended hours increase equipment maintenance and replacement costs. Add roughly 5-8% to your variable costs to account for accelerated wear on ovens, fryers, and other kitchen equipment.
📚 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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