The capacity of school desks should be determined based on the number of users. Single desks are suitable for independent study, offering ample surface area for students to arrange their books and stationery. Double desks save classroom space but require a sufficiently wide surface to ensure both students have their own areas for writing and placing their belongings. Desks designed for three or more students are best suited for specialized activity rooms or training centers; in these cases, the desk's length and stability must be considered to prevent crowding or wobbling during simultaneous use.

Beyond the number of users, the design of the desktop surface is a key factor in determining capacity. Single desks should provide enough width and depth for writing while accommodating books, stationery, or electronic devices. Double desks require greater width-though the depth usually remains the same-to ensure both students can work comfortably. A well-designed desktop enhances learning efficiency and makes it easier for students to organize and access their study materials.

Storage functionality is another crucial aspect of desk capacity. Many modern desks feature drawers or storage compartments for books and stationery, helping to keep the desktop tidy. When selecting desks, one should consider class size and student habits to choose an appropriate storage capacity; this ensures sufficient space for each student while facilitating classroom management and the maintenance of order.