86 Calculator

Instantly know when to 86 a menu item and see the financial impact.

Inventory Rundown by Dish Sold

Dish # Sold	Inventory Remaining

What is an 86 Calculator?

An 86 calculator is a specialized tool for restaurant managers, chefs, and kitchen staff to determine exactly when a menu item needs to be “86’d”—an industry slang term for removing an item from the menu because it has sold out. This calculator moves beyond guesswork by using real-time data: your starting inventory, amount used per dish, and sales so far. It tells you precisely how many portions you can still sell before running out of a critical ingredient, helping you manage customer expectations and maximize revenue from every last bit of inventory.

This tool is essential for anyone running a busy service. Instead of a server taking an order only to find out the kitchen can’t make it, the front-of-house team can be proactively informed. It prevents disappointment and allows staff to guide customers toward other delicious, available options. It’s a cornerstone of effective restaurant inventory management.

The 86 Calculator Formula and Explanation

The logic behind the calculator is straightforward but powerful. It tracks the depletion of a single, critical ingredient for a menu item. The core formula is:

Dishes Remaining = (Total Inventory - (Dishes Sold * Ingredient Per Dish)) / Ingredient Per Dish

This calculation gives you a real-time count of how many more plates you can serve. Our 86 calculator also estimates potential lost revenue if demand outstrips your remaining supply.

Formula Variables

Variable	Meaning	Unit	Typical Range
Total Inventory	The starting quantity of your key ingredient.	grams, oz, lbs, kg, or pieces	100 – 50,000+
Ingredient Per Dish	The amount of that ingredient needed for one portion.	grams, oz, lbs, kg, or pieces	1 – 500
Dishes Sold	The number of portions already sold during service.	Unitless	0 – 200+
Dish Price	The menu price for one portion.	Currency ($)	$10 – $100+

Practical Examples

Example 1: The Steak Frites Special

A bistro has a special on Steak Frites. The limiting ingredient is the 10oz bavette steaks.

• Inputs:
  • Total Starting Inventory: 40
  • Inventory Unit: Units/Pieces
  • Ingredient Used Per Dish: 1
  • Number of Dishes Already Sold: 15
  • Sale Price Per Dish: $32
• Results:
  • Dishes Remaining Before 86: 25
  • Ingredient Left: 25 units
  • Ingredient Used: 15 units

The chef knows they can confidently sell another 25 orders before needing to 86 the special. This is crucial information for planning and for the front-of-house team.

Example 2: Scallop Risotto

A restaurant is tracking its fresh sea scallops for the popular Scallop Risotto. They start the night with 5 kilograms of scallops.

• Inputs:
  • Total Starting Inventory: 5
  • Inventory Unit: Kilograms (kg)
  • Ingredient Used Per Dish: 120 (grams)
  • Number of Dishes Already Sold: 22
  • Sale Price Per Dish: $28
• Results:
  • Dishes Remaining Before 86: 19
  • Ingredient Left: 2360 g (2.36 kg)
  • Ingredient Used: 2640 g (2.64 kg)

By using the calculator, the manager sees they have 19 portions left. If they typically sell 30 portions a night, they can alert staff early that they will likely run out, preventing issues later in the service.

How to Use This 86 Calculator

Using this tool effectively can transform your service flow. Follow these simple steps:

1. Enter Starting Inventory: At the beginning of service, input the total amount of your key ingredient for a specific dish.
2. Select the Correct Unit: Choose the unit that matches your inventory (grams, oz, pounds, kg, or unit/pieces). This is a critical step for accurate calculations. For items like fish fillets, choose ‘Units/Pieces’.
3. Define Ingredient Per Dish: Enter how much of the ingredient (in the same unit) is used in a single order. If your unit is ‘Units/Pieces’, this will almost always be ‘1’.
4. Update Dishes Sold: As orders come in, update the ‘Number of Dishes Already Sold’ field. This is the most important real-time input. Many kitchens use a clicker or a designated person to track this.
5. Set Dish Price: Input the menu price to enable the potential lost revenue calculation.
6. Analyze the Results: The calculator will instantly update, showing you exactly how many dishes are left. Use this number to inform your FOH and BOH teams. The chart and table provide a clear visual breakdown of your inventory status. Exploring a food cost calculator can further refine your menu’s profitability.

Key Factors That Affect When to 86 an Item

While the math is simple, the decision to 86 an item involves several strategic factors. This is where menu engineering comes into play.

• Popularity and Demand: High-demand items deplete faster. Knowing an item’s sales velocity helps you predict when it will need to be 86’d.
• Profit Margin: You are more concerned about running out of a high-profit item than a low-margin one. Prioritize tracking your most profitable dishes.
• Ingredient Spoilage: For highly perishable items like fresh fish or produce, the goal is often to sell out by the end of the night. An 86 calculator helps you pace sales to avoid waste.
• Par Levels: The calculation is based on your starting inventory, which should be determined by your established par levels. Incorrect par levels are a common source of inventory problems. Understanding your par level is fundamental.
• Supplier Reliability: If an ingredient is difficult to source or has an unreliable supply chain, you should monitor its inventory very closely.
• Ease of Substitution: Can you easily substitute another ingredient if you run out? If not, the decision to 86 is more critical.

Frequently Asked Questions (FAQ)

Where does the term “86” come from?

The exact origin is debated, but popular theories include it being code from Chumley’s bar at 86 Bedford Street in NYC, which had many exits to evade police during Prohibition. Another theory points to Article 86 of the NY Liquor Code, which defined when a customer should be cut off. Regardless of origin, it’s universal kitchen slang for “sold out” or “get rid of.”

How often should I update the calculator during service?

For best results, update the “Dishes Sold” field in real-time or as close to it as possible. The more up-to-date the data, the more accurate your “Dishes Remaining” count will be.

What if my dish has multiple critical ingredients?

Track the ingredient you are most likely to run out of first. This is your “limiting factor.” You can run separate calculations for each critical ingredient if necessary.

What does ‘Potential Lost Sales’ mean?

This is an estimate we removed from the main calculator for simplicity but is a concept to consider. It would project how many more dishes you *could* have sold based on average sales velocity if you hadn’t run out, and multiplies that by the dish price. It shows the financial cost of running out of stock.

Can I use this for bar inventory?

Absolutely. Instead of grams, you can use milliliters or ounces to track a specific liquor for a popular cocktail. Set the unit to grams and think of it as ml for a 1:1 conversion. It works perfectly for tracking bottles of wine or special spirits.

How do I handle ‘Units/Pieces’ correctly?

Select ‘Units/Pieces’ as your unit. Set ‘Total Starting Inventory’ to the number of pieces you have (e.g., 40 steaks). Set ‘Ingredient Used Per Dish’ to ‘1’. The calculator will then simply count down the number of pieces you have left.

Why is knowing when to 86 an item important for SEO?

This is more of a business strategy question, but it impacts customer experience, which in turn affects online reviews and reputation. A restaurant that manages its inventory well provides a smoother, more professional experience, leading to better reviews which can positively impact local SEO rankings.

Does this replace a full inventory management system?

No. This is a lightweight, service-focused tool for real-time decision-making on the floor. A full inventory system tracks all ingredients, costs, suppliers, and long-term data. This 86 calculator is a tactical tool for the heat of the moment, which complements larger systems and helps improve your cost of goods sold.

Related Tools and Internal Resources

Optimizing your restaurant operations goes beyond just knowing when to 86 an item. Explore these other calculators and guides to improve profitability and efficiency:

• Food Cost Percentage Calculator: Determine the profitability of each item on your menu.
• Restaurant Profit Margin Calculator: Get a high-level view of your business’s overall financial health.
• Menu Engineering Worksheet: Strategically analyze and optimize your menu for both popularity and profitability.
• Kitchen Slang Glossary: A comprehensive guide to terms like 86, “on the fly,” and “all day.”
• Par Level Inventory Guide: Learn how to set effective inventory levels to minimize waste and stockouts.
• Guide to Cost of Goods Sold (COGS): Understand how to calculate and reduce one of the biggest expenses in a restaurant.