You already know containers are tough, secure, and easy to place. What you may still need is a clear sense of which size matches your load, your site, and your budget. I help buyers and renters make clean size decisions by focusing on real interior space, door clearance, pallet counts, and the kind of items you plan to store. Most people search for shipping containers with only a rough idea of size. A few proven rules and real measurements fix that fast.
Here I walk you through the sizes you will see most, what each can hold, and a short set of selection steps you can use today. I also point you to a provider I trust for Montana projects, because a strong supplier removes guesswork on condition, delivery, and price.
How to Think About Container Capacity
Make your size choice with four checks:
- Footprint: Length and width must fit the placement area with room for delivery trucks to maneuver.
- Interior space: Length, width, and height drive total usable volume.
- Door opening: Tall items, pallets, and equipment must clear the door frame.
- Item type: Loose items need different planning than palletized goods or a vehicle.
I also suggest you sort your load into three groups:
1. Bulky but light items like furniture or seasonal inventory.
2. Dense items like tools, bagged material, or parts bins.
3. Large single items like side-by-sides, small tractors, or long lumber.
This split helps you see if you need height, length, or floor strength most.
The Size Lineup and What Fits
Below are the most common sizes you will run into and what they handle well. Measurements vary a bit by manufacturer. Use these as working guides.
10-foot containers
Compact, easy to tuck beside a house, shop, or small job site.
What they fit well:
- 1 to 2 rooms of furniture and boxes
- 4 to 5 standard 48×40 pallets
- Lawn tractors, motorcycles, and tool carts
- Job boxes and hand tools for small crews
Best for tight spaces or short projects.
20-foot standard containers
The most popular all-around choice for homes and small businesses. Typical interior on quality units is close to 19 feet 4 inches long, 7 feet 8 inches wide, and 7 feet 10 inches high.
What they fit well:
- 2 to 3 bedrooms of furniture and boxes
- 10 to 11 standard pallets single stacked
- Long items up to 19 feet, like lumber, pipe, or staging
- Side-by-sides, ATVs, and compact shop gear
- Construction materials for small to mid jobs
Why people pick 20-foot units:
- Good capacity without taking over a driveway or pad
- Easier placement on tight rural lots and city sites
- Lower monthly rental cost than a 40
40-foot standard and high cube containers
If you need serious capacity or plan to stage a project inside the box, a 40-foot unit makes sense. Many providers carry both standard height and high cube. High cube adds extra interior height that helps with tall racking and equipment. A common high cube interior falls near 39 feet 5 inches long, 7 feet 8 inches wide, and 8 feet 10 inches high.
What they fit well:
- 4 to 5 bedrooms of furniture and boxes
- 20 to 21 standard pallets single stacked
- Pallet racking with an extra shelf tier in high cube units
- Vehicles, small tractors, implements, and large shop tools
- Bulk inventory and warehouse overflow
- Build-outs like simple workshops or project offices
Why people pick 40-foot units:
- Nearly double the storage of a 20
- Height in high cube for tall gear and racking
- Strong platform for custom conversions
Choosing Between 20 and 40 Feet
Use these fast rules if you feel stuck:
- Site space tight or delivery path short: 20-foot.
- Storing a vehicle plus gear or using racking: 40-foot, high cube if possible.
- Short project under three months: rent a 20-foot unless volume proves otherwise.
- Two dozen pallets or more, or large seasonal peaks: 40-foot.
- Unsure on length but sure you need height: 40-foot high cube.
If you plan pallet use, also check door width, door height, and floor condition. Standard forklifts and pallet jacks need a smooth deck.
A Montana Option I Recommend
If you work in Montana and want a straight path to the right unit, take a look at MoCan Containers. They are a locally owned, family-operated provider with large inventory in Billings and Gallatin Gateway near Bozeman. They focus on 20-foot and 40-foot units in both new one-trip and used grades. Every container is inspected for secure doors, sound floors, solid seals, and wind and watertight performance. That level of screening helps you avoid surprises after delivery.
Here is why I point readers to them:
- Real selection: One of the largest inventories within a 300-mile radius, which improves your odds of finding the exact condition and color you want.
- Clear condition: You can inspect and select the exact unit at the yard. The same unit shows up at your site.
- Strong specs: Units are lockable, leakproof, and ready for Montana weather.
- Flexible options: Sales and rentals, short term and long term, with rental rates that start at $150 per month for 20-foot units and $190 per month for 40-foot units.
- Smooth placement: Tilt-bed delivery with guidance on space needs. Plan on about 70 feet of clear space for a 20-foot drop and about 100 feet for a 40-foot drop.
- Custom work: They handle modifications for workshops, offices, retail uses, garages, and more.
If you want a no-nonsense buying or renting process and need delivery across Billings, Bozeman, Yellowstone County, Gallatin Valley, Paradise Valley, and much of central and eastern Montana, they are a solid choice.
Practical Packing Tips by Size
Make space work harder by packing with intent. Here is how I set up each size.
20-foot setup:
- Place heavy tools, safes, and dense bins on the floor across the full width to balance weight.
- Use uniform totes to stack cleanly to the ceiling.
- Create a simple center aisle with shelving on both sides for fast access.
40-foot setup:
- Use pallet racking or metal shelving to use the full height, especially in high cube units.
- Stage vehicles or large equipment in first, then load lighter items above and around.
- If you plan frequent access, split the box into zones with a clear center walkway.
10-foot setup:
- Keep a short aisle and rotate seasonal items to the front.
- Mount hooks and rails to use wall space for long tools and ladders.
Final Take
Pick the smallest container that fits your largest items with room to move, then load it to the ceiling with a clear aisle. If you work in Montana, MoCan Containers gives you reliable 20-foot and 40-foot choices, fair rental and purchase paths, and delivery that saves time on site. If you need a custom build, they can help shape the box to your project.
If you follow the size rules above and match them to your load list, you will get the right container on the first try and keep your project on track.