BETA APP IN DEVELOPMENT HACCP and more are available in your dashboard — currently in beta, so minor bugs may occur. The updated app with full integration is coming soon.
📝 Cost reduction & efficiency · ⏱️ 2 min read

How do I calculate the cost difference between homemade and purchased base preparations?

📝 KitchenNmbrs · updated 14 Mar 2026

Every month, restaurant owners face the same dilemma: make it yourself or buy it ready-made? Most kitchens purchase everything without calculating what homemade actually costs them. You'll discover exactly how to determine what's truly cheaper for your operation.

Why this calculation matters for your bottom line

Restaurant owners often assume that making everything from scratch saves money. But that's not always the case. Labor time changes everything. That €3.50 jar of pesto might actually cost less than homemade if your chef spends 45 minutes preparing it.

⚠️ Heads up:

Labor time can't be ignored. A chef earning €18 per hour makes that pesto cost €18 in wages alone. Then add your ingredients on top.

The real cost formula

Homemade = Ingredient costs + (Labor time × Chef hourly rate) + Energy costs

Purchased = Purchase price per unit

The gap between these numbers reveals your answer. Always calculate per portion or per 100 grams for fair comparison.

💡 Example: Pesto breakdown

Homemade (250 grams):

  • Basil: €2.80
  • Pine nuts: €4.20
  • Parmesan: €3.50
  • Olive oil: €1.10
  • Garlic: €0.40
  • Labor (45 min × €18/hour): €13.50

Total homemade: €25.50 for 250g = €10.20 per 100g

Purchased pesto: €3.50 per 100g

Difference: €6.70 per 100g cheaper to buy!

Hidden expenses you're probably missing

Beyond ingredients and labor, several costs slip under the radar:

  • Energy expenses: Ovens, mixers, and blenders consume electricity
  • Waste and trimming loss: Peels, scraps, ruined batches
  • Storage costs: Refrigerator space isn't free, fresh items spoil
  • Purchasing time: More ingredients mean more ordering complexity
  • Quality inconsistency: Homemade can fail, purchased stays consistent

I've seen this mistake cost restaurants EUR 200-400 monthly because they overlook these hidden expenses and assume homemade always wins.

💡 Example: Mayonnaise comparison

Homemade (1 liter):

  • Egg yolks (6 pieces): €1.80
  • Oil (750ml): €2.25
  • Vinegar, mustard: €0.45
  • Labor (20 min × €18/hour): €6.00
  • Failure risk (10%): €1.05

Total homemade: €11.55 per liter

Purchased mayo (catering): €8.50 per liter

Difference: €3.05 per liter cheaper to buy

Times homemade actually pays off

Buying isn't always the winner. Making your own often works for:

  • Simple preparations: Vinaigrette, herb butter, basic marinades
  • High-volume items: Large quantities justify the labor investment
  • Quality gaps: Purchased versions that taste noticeably worse
  • Signature recipes: Your unique sauces can't be bought
  • Lower labor costs: Interns or available downtime

💡 Example: Herb butter breakdown

Homemade (500 grams):

  • Butter: €4.50
  • Parsley: €1.20
  • Garlic: €0.30
  • Labor (10 min × €18/hour): €3.00

Total homemade: €9.00 for 500g = €1.80 per 100g

Purchased herb butter: €3.20 per 100g

Difference: €1.40 per 100g cheaper to make yourself

Focus on what matters most

Target the preparations you use heavily. Five kilos of mayonnaise monthly? That calculation has serious impact. But 200 grams of truffle paste? The difference barely registers.

⚠️ Heads up:

Calculate only your top 10 most-used preparations. Going beyond that wastes more time than it saves money.

Your decision-making framework

Build a simple spreadsheet for your highest-volume preparations. Track these numbers:

  • Homemade cost per 100 grams
  • Purchased cost per 100 grams
  • Monthly usage volume
  • Total monthly impact

Chase the biggest savings first. A preparation saving €0.20 per 100 grams becomes €40 monthly if you use 20 kilos.

How do you calculate cost difference? (step by step)

1

Calculate homemade costs

Add up all ingredient costs. Calculate labor time: minutes × chef hourly rate ÷ 60. Add energy costs and 5-10% for waste.

2

Determine purchase price of comparable product

Find a qualitatively comparable purchased product. Pay attention to package size and convert to the same unit (per 100g or per liter).

3

Calculate the difference and impact

Subtract the costs from each other. Multiply by your monthly usage to see the total impact. Focus on the biggest savings first.

✨ Pro tip

Calculate your 3 heaviest-used sauces first - track exact quantities over 2 weeks to get accurate usage data. These high-volume items typically offer the biggest potential savings.

Calculate this yourself?

In the KitchenNmbrs app you can do this in just a few clicks. 7 days free, no credit card.

Try KitchenNmbrs free →

Was this article helpful?

Share this article

WhatsApp LinkedIn

Frequently asked questions

Should I always factor in the chef's hourly wage?

Absolutely. Even if your chef's already on shift, that time has value and could generate revenue elsewhere. Labor costs are real costs, not theoretical ones.

How do I calculate energy costs for small batches?

For small quantities, energy costs are usually negligible. But for large batches or power-hungry equipment, add €0.10-0.30 per operating hour.

What if purchased quality doesn't match homemade?

You're comparing different products then. Find purchased options with comparable quality, or accept you're paying extra for superior taste and consistency.

How frequently should I recalculate these numbers?

Review your top 5 preparations quarterly. Ingredient prices and supplier costs shift regularly, so your calculations need updates to stay accurate.

What about items I can't purchase anywhere?

Signature sauces and unique recipes must be made in-house. Still calculate their true costs so you know your minimum profitable selling price.

Should I include equipment depreciation in my calculations?

For specialized equipment used only for specific preparations, yes. Divide annual equipment costs by usage hours to get an hourly rate.

ℹ️ This article was prepared based on official sources and professional expertise. While we strive for current and accurate information, the content may differ from the most recent regulations. Always consult the official authorities for binding standards.

📚 Sources consulted

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.

JS

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.

🏆 8 years kitchen manager at 1NUL8 Group Rotterdam
Expertise: food cost management HACCP kitchen management restaurant operations food safety compliance

Save up to 15% on your food cost

Most kitchens save 8-15% on food cost as soon as they start measuring. KitchenNmbrs makes measuring simple. Start your free trial today and see the difference.

Start free trial →
Disclaimer & terms of use

Table of Contents

💬 in 𝕏