How to Select the Right Size Bus For Your Organization

This article was reviewed and updated on December 23, 2025.

Finding the "Goldilocks" bus for your group

A bus is a significant financial commitment, so it is crucial to select the exact right size for your organization.

If you select a vehicle that is too big, you end up paying for empty seats and higher fuel costs. However, if you go with one that is too small, you risk leaving members behind or forcing the use of additional personal vehicles.

Proper planning before your purchase will save you money and headaches down the road. Here is how to determine the perfect fit.

1. Start smart: The case for conservative growth

It does not matter if you run a local church or a tourism business—smart scaling works best.

Why? Because a bus that sits on the lot only partially full drains resources. It is often easier to upgrade to a larger bus later than to absorb the depreciation and operating costs of a massive coach that isn't fully utilized.

The Fleet Strategy: If you are a larger organization, consider if you need one massive vehicle or a fleet of smaller ones. Adding to your fleet after a careful study of demand allows you to grow without risking profit.

2. Does your audience truly need a bus?

First, determine the nature of your transport needs.

Hotels, for example, often partner with nearby attractions to offer shuttle services. In these high-frequency, short-distance scenarios, a smaller, nimble shuttle bus is often better than a large touring coach.

Survey Your Members: The best way to gauge the level of interest is to ask. Send a survey to your congregation or members to see how many would actually utilize group transport for events versus driving themselves.

3. Navigating size thresholds and CDL laws

The most common size thresholds for commercial buses are 15, 25, and 35+ passengers. When choosing between them, you must consider the legal requirements for your drivers.

• 15 Passengers (Non-CDL): This is the "sweet spot" for many groups. In most states, a bus rated for 15 passengers (14 riders + 1 driver) does not require a Commercial Driver's License. This makes finding volunteer drivers much easier.
• 16+ Passengers (CDL Required): Once you step up to a 20, 25, or 40-passenger bus, federal law requires the driver to hold a CDL with a Passenger endorsement.

The Decision: Study competing organizations or similar churches to learn their audience sizes. Collect any local attendance data you can. If you are unsure and lack CDL drivers, it may be safer to start with a 15-passenger model until your organization has grown enough to make a larger model—and the professional driver required to operate it—a sure thing.

We help you size it right

At Carpenter Bus Sales, we don't just want to sell you a bus; we want to sell you the right bus.

If you are debating between two sizes, give us a call. We can help you calculate the total cost of ownership for different capacities. Call us today at 1-800-370-6180.

Frequently Asked Questions

What is the most popular bus size?

The 15-passenger bus is the most popular volume seller, largely because it does not require a CDL. The 25-passenger bus is the next most common step up for growing organizations.

Can I drive a 25-passenger bus with a regular license if only 5 people are on it?

No. The CDL requirement is based on the vehicle's design capacity and Gross Vehicle Weight Rating, not the number of people currently on board. If the bus has 25 seats, you need a CDL to drive it, even if it's empty.

Is it expensive to upgrade later?

Not necessarily. Commercial buses, especially clean 15-passenger models, hold their resale value well. Many organizations trade in their smaller bus for a larger one 3 to 5 years later as their ministry grows.

How wide are these buses?

Most commercial buses (both 15 and 25 passenger) are built on a "wide-body" design, usually about 96 inches wide (excluding mirrors). This allows for a center aisle and 2+2 seating.

Do larger buses get worse gas mileage?

Marginally. A 15-passenger bus and a 25-passenger bus are often built on similar chassis (like the Ford E-Series). The larger bus is heavier and will consume slightly more fuel, but the difference is often only 1-2 MPG.

About the Carpenter Bus Sales Editorial Team

This article was prepared and reviewed by the Carpenter Bus Sales Editorial Team, drawing on decades of experience serving church, school, and organizational transportation needs nationwide. Carpenter Bus Sales has specialized in bus sales and service since 1953.

Learn more at CarpenterBus.com.