The 80% Rule of Thumb-Handout

June 10, 2015
The 80% Rule of Thumb-Handout

The voice on the other end of the phone sounded perplexed. “How come we can’t seem to grow larger than 100 people,” asked the pastor.
As the conversation continued, I learned that during the pastor’s 15-year tenure his church had experienced three different years when the worship attendance averaged above 100. However, in each case, the church couldn’t maintain the higher attendance and it dropped back below 100 the following year.

Further research revealed that the peaks and valleys of attendance came in patterns. One year the church averaged 115 worshipers. But then worship attendance dropped to an average of 84 worshipers during the following three years before it once again rose to 105. Throughout the pastor’s 15 years of ministry, the church had gone through three similar cycles.

While visiting a Sunday morning worship service, I estimated that the pews would comfortably seat about 100 people. The answer to the pastor’s question was fairly obvious. The church was experiencing the “80% Rule of Thumb.”
Win Arn labeled this the “87:100 Worship Attendance Ratio.” It means that “when 87 of every 100 seats are filled on an average Sunday morning, worship attendance will begin to plateau” (Church Growth Ratio Book, 1987). The rule holds true in all sizes of churches: small, medium, or large.

Understanding the Basics
The 80% Rule is a well know concept of church ministry. However, it may be helpful to consider some of the basics.

1. The 80% rule is based upon a church’s weekly average worship attendance.
The most accurate calculation of this rule of thumb should use an average worship attendance, which includes every Sunday in a given year. In this way, the high Sundays balance out the low ones to give an accurate picture of worship attendance.

2. The 80% rule is based on the total number of seats available to the congregation.
Seats in the choir loft or on the platform are not to be used in the total count, and only one-half of the seats in a balcony should be counted. Carefully observe the number of seats actually used in pews and use only that number in calculating seating capacity.

3. The 80% rule is based on the ratio of attendance to total seats available.
Once you know your average worship attendance per Sunday for a given year, divide that number by the total number of available seats. For example, an average worship attendance of 150 divided by 200 available seats equals a 75:100 ratio. A ratio of 80:100 or greater indicates a church will begin to plateau in attendance.

Why Does It Work?

A number of years ago anthropologist Edward T. Hall conducted a pioneering study on the effects of distance in relationships. He found four main body-space zones: Intimate, Personal, Social, and Public.

The Public Zone is the distance at which pastors, teachers, and lecturers most often stand in relation to their  audience. This zone operates when there is a space of 12 feet or more between speaker and listener.

The Social Zone is the distance we often stand apart from each other when talking in a small group. This zone  is between 4-12 feet and is suitable for fairly impersonal exchanges such as meetings or interviews.

The Personal Zone is the distance we approach when coming within normal touching range of another person.  This zone is thought to be within 18 inches to 4 feet of an individual. People often attempt to protect  their personal zones by placing handbags, coats or other barriers between themselves and others.

The Intimate Zone is the distance we use for embracing. We just allow family members or close friends into this  zone. For North Americans and Europeans, any invasion by strangers into this zone causes mental and  physical anxiety, irritation, and fear.
When attendance exceeds 80% capacity, people are forced into an uncomfortably close seating arrangement. The 80% Rule of Thumb comes into play because the Personal and Intimate Zones of worshipers are invaded.

Of course, certain dynamics may bring people into close proximity for a short while, but eventually the tension created through invasion of their personal and intimate zones forces the attendance back down as some attend less often and others depart to relieve the tension. While attendance may exceed 80% for a while, it will do so just temporarily.

What Can We Do about It?

There are at least seven approaches to alleviating the 80% problem.
#1: Expand the seating capacity. If the space is available, a church can put in additional seats. In some cases,  using a different style of seat or a different arrangement can add significantly more seating to an  otherwise full auditorium.

#2: Remodel or build a sanctuary.  A sanctuary can be remodeled to add a balcony, to enlarge the room size  to allow for more seats, or a new worship center can be built to hold the growth.

#3: Add new worship services: A popular option is the use of multiple worship services on a Sunday morning  or other evenings of the week. This approach is very cost effective as facilities don’t need to be  remodeled or new ones built.

#4: Plant a daughter church. Spinning off worshipers to plant, a daughter church relieves the overcrowding at  the mother church temporarily. However, the people who leave are usually replaced within a year and  the problem presents itself once again.

#5: Start a satellite church. An approach, which should be considered more often, is the starting of a satellite  church. The church becomes one church meeting in two or more locations.

#6: Use overflow rooms. Establishing overflow rooms, where the service is delivered through video projection,  is a good approach but most often a temporary one.

#7: Begin house churches: Establishing house churches, where worshipers attend church one Sunday a  month, relieves overcrowding at the main facility by about 25%. Once again, this approach is a  temporary stopgap measure rather than a long-term answer.

Is the 80% Rule of Thumb affecting your church? If so, what are you going to do to increase your potential for growth?

Dr. Gary McIntosh is a consultant, author and Professor of Christian Ministry & Leadership at Talbot School of Theology, and editor for Church Growth Network newsletter. For additional information, check out his website at

© Dr. Gary L. McIntosh, used with permission.

For an onsite evaluation of your present facilities, or consulting on planning for remodeling and/or new construction, contact the Evangelism and Church Health Team of the Arkansas Baptist State Convention, 1-800-838-2272