Choosing the right suitcase can make or break your travel experience. Too small, and you’ll struggle to fit everything in. Too large, and you risk extra airline fees or hauling unnecessary weight. If you’ve ever wondered what size suitcase do I need, this comprehensive suitcase size guide will help you decide with confidence.

What size suitcase do I need?

Before diving into specifics, it’s important to understand the five main suitcase size categories:

Cabin (carry-on) luggage

Cabin suitcases are designed to fit in the overhead compartment on most airlines. They’re typically around 55 x 40 x 20 cm, though this can vary slightly.

• Best for short trips (1 - 3 days)
• Ideal for light packers or business travel
• Helps you avoid checked baggage fees

Medium suitcases

Medium-sized luggage usually falls between 60 - 70 cm in height and offers a balance between space and portability.

• Suitable for trips lasting 4–7 days
• Popular choice for solo travellers
• Easier to manage than large suitcases

Large suitcases

Large suitcases are typically 70ccm or more and provide maximum packing space.

• Best for long holidays (10+ days)
• Ideal for families or heavy packers
• Often requires checked baggage

Extra-large suitcases

Extra-large suitcases are designed for extended travel and maximum storage capacity. They are usually over 80cm in height and offer substantial room for clothing, shoes, and bulky items.

• Best for trips lasting 2+ weeks
• Ideal for family holidays or long-haul travel
• Great for winter clothing or multiple travellers sharing luggage
• Usually requires checked baggage and careful attention to airline weight limits

Underseat bags

Underseat bags are the smallest travel luggage option and are designed to fit underneath the seat in front of you on a plane. They’re typically smaller than standard cabin luggage and are often included for free with budget airlines.

• Best for overnight stays or weekend trips
• Ideal for minimalist packers
• Convenient for keeping essentials close during flights
• Helps avoid additional baggage fees

Travel duration recommendations

One of the most practical ways to decide what size suitcase do I need is to consider how long you’ll be travelling.

1 - 3 Days

A cabin suitcase is usually sufficient. Pack versatile outfits and limit shoes to maximise space.

4 - 7 Days

A medium suitcase is typically the best option. It offers enough room for multiple outfits, toiletries, and a couple of pairs of shoes without being overly bulky.

7 - 14 Days

Depending on your packing style, you might choose a medium or large suitcase. If you prefer options or are travelling to different climates, a large suitcase may be more suitable.

2+ Weeks

A large or extra-large suitcase is recommended, especially if you won’t have access to laundry facilities. Keep in mind that packing habits matter just as much as trip length. Minimalist travellers may manage with smaller luggage, while others prefer extra space.

What size suitcase is best for a week long holiday?

For most travellers, a medium suitcase is the ideal choice for a 7-day trip. It offers:

• Enough space for 5–7 outfits
• Room for shoes, toiletries, and accessories
• Flexibility for different activities or weather conditions

If you’re a light packer or staying somewhere with laundry facilities, you could potentially downsize to a cabin suitcase. On the other hand, if you like to bring multiple outfit options or plan to shop while away, a large suitcase might be worth considering.

Is cabin luggage enough for a 7-day trip?

The short answer: it depends on how you pack. Cabin luggage can be enough for a 7-day trip if:

• You pack efficiently (think capsule wardrobe)
• You re-wear outfits or do laundry
• You minimise bulky items like shoes and jackets

However, it can feel restrictive if:

• You need different outfits for various occasions
• You’re travelling in colder climates
• You want to bring back souvenirs

If you’re unsure, a medium suitcase provides a safer middle ground.

Should you choose large luggage?

This is one of the most common dilemmas when using a suitcase size guide.

Choose a medium suitcase if:

• You’re travelling for up to a week
• You want easier mobility
• You prefer to pack only essentials

Choose a large or extra-large suitcase if:

• You’re travelling for more than 10 days
• You need space for bulky items (coats, boots)
• You’re travelling as a couple or sharing luggage

A helpful tip: it’s often better to slightly under-pack a large suitcase than to overstuff a medium one. Overpacking can make your suitcase difficult to close and more prone to damage.

Airline size limits: What you need to know

Cabin luggage limits

• 55 x 40 x 20 cm but can be up to 56cm x 45cm x 25cm
• Weight limits typically range from 7 - 10 kg
• Budget airlines may have stricter rules, so always check in advance.

Checked baggage limits

• Standard weight allowance is usually 20 - 23 kg
• Size is often measured as total dimensions (height + width + depth), typically up to 158 cm

Exceeding these limits can result in additional fees, so choosing the right suitcase size is essential.

How do airlines measure suitcase sizes?

Airlines measure suitcase size in two main ways:

1. External suitcase dimensions

This includes:

• Wheels
• Handles
• Pockets

Even if the internal storage is smaller, the full external size must comply with airline rules.

2. Total Linear Dimensions

For checked baggage, airlines often use a combined measurement:

Height + width + depth

For example, a suitcase measuring 75 x 50 x 30 cm has a total dimension of 155 cm, which typically falls within standard limits. Some airlines use baggage sizers at the airport to check if your carry-on fits within the allowed dimensions. If it doesn’t fit, you may be required to check it in and pay a fee.

Choosing the right suitcase size doesn’t have to be complicated. By considering your trip length, packing style, and airline restrictions, you can confidently decide what size suitcase do I need for your next holiday.

As a quick recap:

Using a clear luggage size chart and planning ahead will help you avoid unnecessary stress at the airport and ensure you travel comfortably from start to finish.