On average, building a custom or built-in closet costs around $2,100. However, the total price can range from as little as $500 for a simple DIY project to $6,000 or more for a large, high-end custom closet. Most projects typically fall between $1,500 and $5,000.

The final cost depends on several factors, including the closet's size, type, materials, and features. Here is a general cost breakdown by closet type:

• Reach-in closet: $500 to $1,500

• Walk-in closet: $750 to $5,000

• Wardrobe: $2,000 to $6,000 or more

Choosing a prefabricated closet system is generally less expensive than a fully custom build. The scope of design and construction services will also significantly impact the price.

There are a few reasons custom closets are expensive: materials used, the luxury factor, and time to build. The people who can afford custom closets are those who can afford increased rates, and construction workers and contractors know this and charge accordingly. The time to build custom closets is substantial, especially if expensive material is being used or intricate details (like carved wood) are added to the project. 

A standard walk-in closet has dimensions of 7 feet by 10 feet at a minimum and an average of 100 square feet. Remember that the dimensions of the closet aren’t necessarily the usable space. This means that a 100-square-foot walk-in closet with shelves on each wall and an island may only have a walkable area of 50 square feet or less. Make sure you consider the effect of additions when you plan the room—mockups are a great idea.

Walk-in closets are always the biggest and can easily be more than 100 square feet. Primary bedroom closets, even if not walk-ins, are the second largest category in most homes and sit between 30 and 80 square feet. Linen closets, utility closets, and built-in closets are smaller and, depending on their usage, tend to be between 10 and 50 square feet.