--- title: What Size Storage Unit Do I Need? | Sparks Self Storage url: https://sparksselfstoragellc.com/guides/what-size-storage-unit/ business: Sparks Self Storage LLC phone: (608) 412-4263 address: 35068 WI-27, Prairie du Chien, WI 53821 access: 24/7 access is available on request for an additional fee (ask when you rent) --- - [Home](https://sparksselfstoragellc.com/) - [Guides](https://sparksselfstoragellc.com/guides/) - What size storage unit do I need? # What size storage unit do I need? Start with the biggest things you're storing and how much of a home you're emptying. A 10x20 (200 sq ft) is about the footprint of a one-car garage and fits the contents of a multi-room home or most cars; a 10x30 (300 sq ft) is about a large one-and-a-half to two-car garage and holds a large home or a boat on its trailer; a 10x40 (400 sq ft) fits a full home or vehicles plus gear. ## Step by step - ### List the big items first Furniture, appliances, mattresses, a car, a boat or a trailer decide the size - boxes fill in around them. - ### Match the floor area A 10x20 is 200 square feet, about the footprint of a classic one-car garage; a 10x30 is 300 square feet, about a large one-and-a-half to two-car garage, though deeper and narrower [[1]](#src-h) . - ### Think in rooms A 10x20 can comfortably store the contents of a three-bedroom home, and a 10x30 the furniture and belongings of a four-plus-bedroom house when packed well [[1]](#src-h) . Room counts are rough - how you pack matters. - ### Check vehicles and boats Almost any car fits in a 10x20, but two cars won't. A 10x30 can hold two cars end to end, and boats and RVs are commonly stored in units that size or larger [[1]](#src-h) . - ### Use the height Most of our units have 8- to 10-foot ceilings, so shelving and stacked boxes let a smaller unit hold more. - ### Leave a walkway Plan a path down the middle so you can reach things without unpacking everything [[2]](#src-h) . If it's tight, go one size up. ## Our sizes at a glance | Unit | Floor area | About the size of | Good for | Monthly rate | | [10x20](https://sparksselfstoragellc.com/storage-units/10x20/) | 200 sq ft | the size of a one-car garage | The contents of a multi-room home or apartment, a car, tools and trade equipment, seasonal gear | [Call for today's rate](tel:+16084124263) | | [10x30](https://sparksselfstoragellc.com/storage-units/10x30/) | 300 sq ft | a large one-and-a-half to two-car garage | The contents of a large home, appliances, motorcycles, a small boat or trailer, business inventory | [Call for today's rate](tel:+16084124263) | | [10x40](https://sparksselfstoragellc.com/storage-units/10x40/) | 400 sq ft | a large two-car garage | A full home, long-term moves, vehicles and trailers, boats, ATVs and snowmobiles, bulk business storage | [Call for today's rate](tel:+16084124263) | Still not sure? Tell us what you're storing on the [reservation form](https://sparksselfstoragellc.com/contact/#contact-form) and we'll help you pick. ## Sources - [StorageCafe - Large storage units explained: how to know what size you need (July 2, 2026)](https://www.storagecafe.com/blog/large-storage-unit-guide/) - 10x20 = one-car garage footprint, three-bedroom home, almost any car; 10x30 = two-car garage footprint, four-plus bedrooms, two cars, boats and RVs - [U-Haul Moving Insider - How to pack a self storage unit (Jan. 24, 2013)](https://www.uhaul.com/Blog/2013/01/24/how-to-pack-a-self-storage-unit) - leave a walkway through the middle of the unit Sources accessed October 19, 2026. Follow your owner's manual for your own vehicle, boat or equipment. At Sparks Self Storage: 75 drive-up 10x20, 10x30 and 10x40 units on Highway 27 in Prairie du Chien, month-to-month, free disc lock with every new rental. [See the units](https://sparksselfstoragellc.com/storage-units/). ## More guides - [How to pack a storage unit](https://sparksselfstoragellc.com/guides/how-to-pack-a-storage-unit/) - [Wisconsin winter storage tips](https://sparksselfstoragellc.com/guides/wisconsin-winter-storage/) Rent a unit ## Ready for a unit? Tell us the size you want and when you'd like to move in. We'll call to confirm availability and today's rate. Talk to a person [(608) 412-4263](tel:+16084124263) Our team answers calls and messages 7 days a week 35068 WI-27 Prairie du Chien, WI 53821 [Get directions](https://www.google.com/maps/dir/?api=1&destination=35068+WI-27%2C+Prairie+du+Chien%2C+WI+53821&destination_place_id=ChIJ5bWjRimF_IcRRjE-yl6U8zA)