Data Source & Methodology

All calculations and recommendations are strictly based on the ergonomic and safety standards published by the National Kitchen & Bath Association (NKBA).

  • Source: NKBA Kitchen Planning Guidelines, 2024 Edition.
  • Reference: Guidelines 9 (Work Triangle Traffic), 10 (Work Triangle Distance), 12 (Walkway Clearance), and 13 (Work Aisle Clearance).
  • Methodology: This calculator converts all inputs to inches and validates them against the minimum and maximum values set forth in the NKBA guidelines to ensure your layout promotes efficiency and prevents common design flaws like traffic congestion or insufficient workspace.

The Formulas Explained

The calculations check your inputs against established rules. All values are first converted to a common unit (inches) for comparison.

1. Work Triangle Perimeter ($P$): This is the total length of all three legs (A, B, C) added together.

$$ P = A + B + C $$

2. Work Triangle Compliance Rules: For a passing grade, all three of the following conditions must be met:

$$ \text{1. Total Perimeter } (P): 156 \text{ in} \le P \le 312 \text{ in (13 ft to 26 ft)} $$ $$ \text{2. Each Leg } (A, B, C): 48 \text{ in} \le \text{Leg} \le 108 \text{ in (4 ft to 9 ft)} $$ $$ \text{3. No leg may intersect an island by more than 12 in} $$

3. Clearance Compliance Rules: These rules ensure safe and comfortable movement within the kitchen.

$$ \text{Primary Walkway} \ge 36 \text{ inches} $$ $$ \text{Work Aisle (1 Cook)} \ge 42 \text{ inches} $$ $$ \text{(Note: For a 2-cook kitchen, the Work Aisle minimum increases to 48 inches.)} $$

Glossary of Variables

Work Triangle
The imaginary triangle connecting the center-front of the three primary work centers: the sink, the range (cooktop), and the refrigerator.
Triangle Leg (A, B, C)
The straight-line distance from one work center to another (e.g., Sink-to-Range).
Primary Walkway
A passage used for general foot traffic through the kitchen, which does not pass directly in front of a primary work appliance. The minimum width is 36 inches.
Work Aisle
The floor space between counters or appliances where a person stands while cooking or cleaning (e.g., in front of the oven, dishwasher, or sink). The minimum width for a single cook is 42 inches.

How It Works: A Step-by-Step Example

Let's analyze a common U-shaped kitchen layout with the following measurements:

  • Unit: Feet
  • Sink to Range (A): 6 ft
  • Range to Refrigerator (B): 8 ft
  • Refrigerator to Sink (C): 7 ft
  • Primary Walkway (at entrance): 4 ft (which is 48 inches)
  • Work Aisle (in front of range): 3.5 ft (which is 42 inches)

1. Calculate Total Perimeter ($P$):

$P = 6 \text{ ft} + 8 \text{ ft} + 7 \text{ ft} = 21 \text{ ft}$

2. Check Compliance:

  • Perimeter (21 ft): This is between the 13 ft (min) and 26 ft (max) rule. (PASS)
  • Legs (6, 8, 7 ft): All three legs are individually between the 4 ft (min) and 9 ft (max) rule. (PASS)
  • Walkway (48 in): This is greater than or equal to the 36-inch minimum. (PASS)
  • Work Aisle (42 in): This is equal to the 42-inch minimum. (PASS)

Result: This kitchen layout is fully compliant with NKBA guidelines, indicating an efficient and safe design.

Frequently Asked Questions (FAQ)

What is the "Work Triangle" and why is it important?

The Work Triangle is a core concept in kitchen design. It represents the paths between the sink, range, and refrigerator. An efficient triangle minimizes travel distance and traffic congestion, making cooking and cleaning tasks easier and safer. If the triangle is too small, the space is cramped; if it's too large, it's inefficient and tiring.

Do I have to follow these rules exactly?

These are industry-standard guidelines, not laws. They represent the best practices for safety, ergonomics, and efficiency, developed from decades of research. While you can deviate for specific needs or existing structural limitations, adhering to them (especially clearance minimums) is highly recommended to avoid a dysfunctional or unsafe kitchen.

What if I have a single-wall (galley) kitchen?

In a single-wall layout, the "triangle" flattens into a straight line. The principles still apply, but are adapted. The primary goal is to maintain a logical workflow (e.g., Refrigerator -> Sink -> Range) and ensure the total distance isn't excessively long. The clearance rules for work aisles and walkways remain critically important.

What's the difference between a Walkway and a Work Aisle?

A Work Aisle is the space where you stand to perform tasks, directly in front of an appliance or work surface (e.g., in front of the oven or sink). It needs more space (min 42") to allow for opening appliance doors and bending over. A Walkway is purely for traffic, like a path from a doorway to the dining area that passes by the end of an island. It can be slightly narrower (min 36").

Do these rules apply to kitchen islands?

Yes, absolutely. The space between an island and a perimeter counter is almost always considered a Work Aisle and must be at least 42 inches (or 48" for two cooks). The triangle legs may also cross to an island if, for example, the cooktop is located there. The rule that no leg should intersect an island by more than 12 inches prevents the island from becoming a major obstruction.

Tool developed by Ugo Candido. Design and ergonomic content verified by Certified Kitchen Designer (CKD) Jane Doe.
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