New Trip Editorial Department Last updated: 2026.06.25

A guide to choosing the right suitcase size: The first step to making travel easier

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Good morning, fellow travel lovers! Have you ever made a mistake choosing the right size suitcase ? I had a bitter experience trying to get through a three-night stay with a small-size suitcase, but it didn't fit a bottle of wine I brought home as a souvenir, so I had to carry it all by hand.

To avoid such tragedies, today we'll be explaining the basics of suitcase sizes ! We'll be digging deeper into S, M, and L sizes in this series, so let's get the big picture straight away. Let's get started on the first step to making your trip easier!

table of contents

1. Suitcase sizes, types and features

2. Carry-on and checked baggage size restrictions

2. Tips for choosing a suitcase depending on the number of days you are traveling

3. Common mistakes when choosing suitcase size and how to avoid them

4. Tips for choosing the right suitcase size for each occasion

summary

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一、スーツケースサイズの目安と選び方【泊数別早見表】

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Suitcases come in three main sizes : S, M, and L. They're divided like clothing sizes, which is simple, but knowing the characteristics of each will make it easier to choose.

宿泊日数 容量目安 サイズ目安 おすすめシーン
日帰り〜1泊 ～25L SSサイズ 出張・イベント・ジム・近場の旅行
1〜2泊 25〜35L Sサイズ 国内旅行・短期出張
2泊3日 30〜45L S〜Mサイズ 週末旅行・荷物多めの国内旅行
3泊4日〜5泊 45〜60L Mサイズ 修学旅行・短期海外旅行
5〜7泊 60〜80L M〜Lサイズ 1週間前後の海外旅行・冬の旅行
7泊以上 80〜100L Lサイズ 長期旅行・家族旅行

Height within 55cm ( including wheels and handles ), capacity approximately 20-40L .

It's perfect for short trips of 1-3 nights , and its biggest appeal is that it can be carried on board .

The best thing about it is being able to move around freely without the hassle of checking it in.

Once, my checked luggage was delayed in Europe, and I had to wait in the lobby on my first day, and ever since then I've been hooked on the convenience of the small size.

<Recommended>

・New Trip Suitcase S size

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二、機内持ち込み・預け入れのサイズ制限

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When using a suitcase on an airplane, in addition to capacity, you need to check the "total dimensions (length + width + height)" and "weight limit."

However, rules vary depending on the airline, route, and seat class, so always check the latest information before your departure.

区分 サイズ目安 重量目安 注意点
機内持ち込み 3辺合計115cm以内 10kg以内が目安 LCCは7kg以内など厳しい場合あり
無料預け入れ 3辺合計158cm以内 23kg以内が目安 Lサイズ・LLサイズは外寸確認が必要
LCC利用 航空会社ごとに異なる 7kg前後が多い サイズ・重量ともに制限が厳しい傾向

機内持ち込みサイズは3辺合計115cm以内が目安

Carry-on suitcase sizes are generally considered to be within 115 cm for the total outer dimensions of three sides. (If the aircraft has fewer than 100 seats, it's usually within 100 cm total.)

 

While ANA and JAL often have a weight limit of 10 kg, low-cost carriers (LCCs) may have stricter weight restrictions, such as 7 kg.

 

If you prioritize carry-on, check not only the capacity but also the weight of the suitcase itself. If the suitcase itself is heavy, you might exceed the weight limit with only a small amount of luggage inside.

預け入れサイズは3辺合計158cm以内が目安

For checked suitcases, a general guideline for free baggage is a total of 158 cm for the sum of the three dimensions.

If you choose an L or LL size, you may incur additional charges if the external dimensions are too large, even if the capacity is sufficient.

 

Also, for international travel, a weight limit of 23kg is a common guideline.

Pay attention not only to the size but also to the weight, especially if you pack a lot of winter clothes, shoes, and souvenirs.
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三、スーツケースサイズの正しい測り方

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Choosing a suitcase based on the number of days you will be traveling will have a big impact on the amount of luggage you will have and how convenient it will be to travel.

This chapter will give you tips on choosing the best size and type for the length of your trip.

確認項目 チェックポイント
高さ キャスター下からハンドル上部まで測る
幅 サイドハンドルなど突起部を含める
奥行き 拡張機能を使った状態も確認する
3辺合計 高さ＋幅＋奥行きで計算する

本体サイズではなく「総外寸」を確認する

On product pages for suitcases, you may sometimes find "body dimensions" and "overall dimensions" or "total external dimensions" listed separately. Since airlines often check the total size, including wheels and handles, when considering carry-on or checked luggage, it's best to use the total external dimensions as your guide.

 

There have been cases where a suitcase's "body alone was within 55cm, but when including the wheels, it exceeded the size limit." Especially when choosing a carry-on suitcase, it's crucial to confirm that the sum of its three sides is within 115cm.

エキスパンダブル機能は拡張後サイズに注意

Suitcases with an expandable function, which allows you to increase their capacity, are convenient when you have more souvenirs after a trip. However, opening the zipper to expand them increases their depth, and the sum of their three dimensions may change.

 

For example, even if a suitcase is within carry-on size before expansion, if the sum of its three dimensions exceeds 115cm after expansion, it may not be allowed as a carry-on. If you plan to use it as a carry-on, be sure to check the external dimensions not only before but also after expansion.

 

In the case of the "New Trip 0201 Plus," the depth increases by approximately 4.5cm after expansion, and the total external dimensions change from approximately 114cm to approximately 118.5cm.

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四、旅行シーン別のおすすめスーツケース

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Choosing the right size suitcase for your travel needs will greatly improve your comfort.

This chapter introduces the optimal sizes for different purposes.

For business travel , a compact suitcase (30-40L) that can be carried on board is ideal. It allows for smooth travel and is convenient for carrying business documents and a laptop.

・Family travel : You will need a suitcase with a large capacity (60L or more). Focus on storage capacity so that you can store clothes and items for the whole family.

For solo travelers and backpackers : A lightweight suitcase (40-50L) is ideal for those who want to travel light and with minimal luggage. Its flexibility and ability to move around easily are its main advantages.

By choosing the perfect size for your travel needs, you can easily organize your luggage and travel smoothly.

国内旅行・短期出張：Sサイズ

For domestic trips of 1-3 nights or short business trips, an S size suitcase of around 30-40L is recommended. This size is easy to carry on airplanes and convenient to handle when traveling by train or Shinkansen.

If you frequently move between stations, it's convenient to choose a size that fits easily into coin lockers, or a model with caster stoppers.

New Trip 0702Plus スーツケース

コインロッカー対応｜都市旅行・短期出張に最適

New Trip 0702Plus スーツケース

約42L｜機内持ち込み対応・コンパクト設計

コインロッカー対応サイズ TSA008ロック YKKファスナー キャスターストッパー

¥21,980

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海外旅行・4〜7泊：Mサイズ

For trips lasting 4 to 7 nights, an M-sized suitcase with a capacity of around 50-70L is a convenient choice. It offers ample space for clothes, toiletries, and souvenirs, making it suitable for both domestic and international travel.

If you're buying your first suitcase or are unsure between an M and L size, starting with an M-sized one is often the easiest option to manage.

New Trip 0201 スーツケース

4〜7泊の国内・海外旅行におすすめ

New Trip 0201

Mサイズ・60L｜ABS+PC

超軽量3.6kg 拡張機能 TSAロック

¥15,680

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長期旅行・家族旅行：Lサイズ

For trips lasting 7 nights or longer, or family trips, a large size over 80L is suitable. This size makes it easy to pack winter clothes or luggage for multiple people, and is also convenient for trips where you plan to buy many souvenirs.

However, note that large suitcases tend to be heavy, so be sure to check that it does not exceed the checked baggage limits of 158cm total linear dimensions or 23kg in weight. For trips involving a lot of movement, it may be easier to handle multiple M-sized suitcases rather than consolidating everything into one large suitcase.

New Trip 0502 スーツケース

7泊以上の長期・家族旅行におすすめ

New Trip 0502

Lサイズ・100L｜PC素材+亜鉛合金コーナーパット

HINOMOTO製静音キャスター 拡張機能 TSAロック 防水ポケット スマホスタンド

¥25,980

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まとめ

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This time we've introduced the basics of suitcase sizes . What did you think? S, M, and L each have their own appeal, and it's interesting to see how your choice changes depending on your travel style.

We'll be looking at each size in detail from now on, and next time we'll be giving a thorough explanation of the " S size "! I'll also be sharing tips for carry-on luggage, my favorite recommended models, and "packing techniques for getting through a three-night stay in an S size." Please look forward to it.


What size are you? Let us know in the comments. See you next time!

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FAQ(よくある質問)

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Q. スーツケースは1泊あたり何リットルが目安ですか？

A. 一般的には、1泊あたり10Lが目安です。2泊3日なら30〜40L前後、3泊4日なら40〜60L前後、1週間の旅行なら60〜80L前後を目安にすると選びやすくなります。

Q. 2泊3日のスーツケースサイズは何Lがおすすめですか？

A. 2泊3日なら、30〜45L前後のS〜Mサイズがおすすめです。荷物が少ない国内旅行なら30〜40L、冬服やお土産が多い場合は40〜45Lほどあると安心です。

Q. 3泊4日のスーツケースサイズはSとMのどちらがいいですか？

A. 3泊4日なら、荷物が少ない場合はSサイズでも対応できますが、お土産や着替えが多い場合はMサイズがおすすめです。容量の目安は40〜60L前後です。

Q. 1週間の旅行には何Lのスーツケースが必要ですか？

A. 1週間の旅行には、60〜80L前後のM〜Lサイズが目安です。夏の旅行や荷物が少ない人は60〜70L、冬の海外旅行や荷物が多い人は80L前後を選ぶと安心です。

Q. MサイズとLサイズはどちらがおすすめですか？

A. 4〜7泊程度で移動が多い旅行ならMサイズ、7泊以上や冬の海外旅行、家族旅行ならLサイズがおすすめです。迷った場合は、扱いやすく汎用性の高いMサイズから検討するとよいでしょう。

Q. 機内持ち込みできるスーツケースサイズは？

A. 一般的には、3辺合計115cm以内、重量10kg以内が機内持ち込みサイズの目安です。ただし、LCCでは7kg以内など制限が厳しい場合があるため、利用する航空会社のルールを確認しましょう。

Q. 無料で預け入れできるスーツケースサイズは？

A. 一般的には、3辺合計158cm以内、重量23kg以内が無料預け入れの目安です。LサイズやLLサイズを選ぶ場合は、容量だけでなく外寸と重量も確認しましょう。

Q. スーツケースのサイズはキャスター込みで測りますか？

A. はい。スーツケースのサイズは、キャスター・ハンドル・サイドハンドルなどの突起部を含めた総外寸で確認します。本体サイズだけで判断すると、空港でサイズオーバーになる場合があります。

Q. 拡張機能を使うと機内持ち込みできなくなりますか？

A. 拡張機能を使うと奥行きが広がるため、3辺合計115cmを超えて機内持ち込みできなくなる場合があります。機内持ち込みで使う予定がある場合は、拡張前だけでなく拡張後の外寸も確認しましょう。

Q. コインロッカーに入るスーツケースサイズは？

A. 駅のコインロッカーに入れやすいのは、SSサイズや小さめのSサイズです。ただし、ロッカーのサイズは駅や設置場所によって異なるため、確実に預けたい場合は利用予定の駅のロッカーサイズを事前に確認しましょう。

執筆・監修

New Trip編集部
本記事は、スーツケース・旅行用品ブランド「New Trip」の編集部により制作されました。
製品開発やユーザーの声を活かしながら、ユーザーに合ったスーツケースや、旅行・出張をより快適にするアイテムを発信しています。

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