Audience size determines working distance and thus presentation style

As I discussed yesterday, presentation style should match the audience size. The working distance between the presenter (you) and the back of the audience will determine how big your gestures should be, whether you need a microphone and sound system to be heard, and what type of visual aids you need to be seen.

If your gestures are too small, they will not be seen and your nonverbal communication will be ineffective. If your gestures are too large, you will be accused of theatrics, histrionics, or being a “drama queen”.

When planning an event, you can use an online calculator to determine the room size. First you must pick the type of seating. Working distance can be estimated based on the audience size and the type of seating. The densest type of seating is theater seating, which requires about nine square feet per person. For example, an audience of 64 people would require a room size (area) of 64 x 9 = 576 square feet. The estimated working distance is the square root of the room size, or 24 feet. The actual distance also depends on the room shape.

For audience sizes ranging from one to about a million, the following table shows a spectrum with twenty distinctly different audience and room sizes (as described by a series of powers of two). The first column shows the exponent, E, the second the resulting audience size, the third the estimated working distance (for theater seating in a square room) and the fourth a typical presentation venue.

E, audience size, estimated working distance, and a typical venue
0 – 1
1 – 2
2 – 4 – 6 ft.
3 – 8 – 8.5 ft. = a conversation in part of a room
4 – 16 – 12 ft.
5 – 32 – 17 ft. = a school classroom
6 – 64 – 24 ft.
7 – 128 – 34 ft. = a university lecture hall
8 – 256 – 48 ft.
9 – 512 – 68 ft. = an auditorium, or theater
10 – 1,024 – 96 ft.
11 – 2,048 – 136 ft. = an opera house
12 – 4,096 – 192 ft.
13 – 8,192 – 272 ft.
14 – 16,384 – 384 ft.
15 – 32,768 – 543 ft. = a basketball arena
16 – 65,536 – 768 ft.
17 – 131,072 – 1,086 ft. = a football stadium
18 – 262,144 – 1,536 ft. = the Indianapolis 500
19 – 524,288 – 2,172 ft.
20 – 1,048,576 – 3,072 ft. = over a half-mile, a visit from the Pope

You should rehearse your presentation in a venue with the same working distance as where it will finally be given. Finding a place to rehearse may require considerable ingenuity. Some possibilities are community centers, churches, or public libraries.