Update date: 2026.03.11

How to Choose an S-Size Suitcase | Carry-on & Recommended Models

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Many people probably wonder, "What size suitcase should I choose?" when preparing for a trip or business trip.
The small size suitcase in particular is a popular size that is perfect for short trips or business trips of 2 to 3 nights .
However, carry-on baggage size restrictions vary by airline, and it's not uncommon for people to buy something only to find they can't take it on board.

In this article,
・Basic size and capacity of small suitcases ・Conditions for carry-on luggage ・Points to consider when choosing

I will explain it in an easy-to-understand way.

In addition, we will introduce recommended models that are lightweight, quiet, and durable .
After reading this article, you'll be sure to find the perfect suitcase for your travel style.

table of contents

1. What is an S-size suitcase? Basic size and features

- Insert size comparison chart (S/M/L)

2. Travel situations where small suitcases are useful

・"Key points at a glance"

3. How to choose an S-size suitcase

4. Three Recommended Small Suitcases [New Trip Series]

5. Top 3 Recommended S-Size Suitcases

・New Trip 0501

・New Trip 0201 Plus

・New Trip 0502

summary

Frequently asked questions (FAQ) about small suitcases

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一、Sサイズのスーツケースとは？何泊向け？

An "S-size suitcase" generally refers to a suitcase with a capacity of around 20 to 38 liters .
As a guideline, this size is ideal for trips or business trips of 1 to 3 nights .
Many domestic airlines allow carry-on luggage as long as the total of the three dimensions is within 115cm (e.g. 55 x 40 x 25cm) and the weight is within 10kg .

■ Sサイズの基本スペック

項目 目安
容量 35〜40L
外寸（3辺合計） 110〜115cm
高さ × 幅 × 奥行 約55cm × 40cm × 25cm
重量 2〜4kg
適した泊数 1〜3泊

💡Most domestic airlines allow carry-on luggage if the total dimensions are within 115cm and the weight is under 10kg. Related article: "Carry-on Luggage Guide: Regulations and How to Choose for International, Domestic, and LCC Flights"

■スーツケースのサイズ比較表（例）

サイズ 容量目安 泊数目安 機内持ち込み
SSサイズ 約20L 1泊 ○
Sサイズ 約35L 1〜3泊 ○（多くの航空会社で可）
Mサイズ 約60L 3〜5泊 ✕
Lサイズ 約90L 7泊以上 ✕

Advantages of S size

・Compact and easy to carry

- No need to check in at the airport, saving time

・Peace of mind knowing your luggage is close at hand on the plane

On the other hand, since the capacity is limited, it is not suitable for trips with lots of souvenirs and clothes .
It's important to determine whether the small size is truly suitable for your travel style and the amount of luggage you'll be carrying.

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二、Sサイズスーツケースのデメリット・メリット

The small size suitcase is perfect for those who want to carry only what they need.
Although it is compact enough to be carried on board, it can still hold enough luggage for 2-3 nights.
It is particularly useful in the following situations:

■ デメリット（Sサイズの構造的な制約）

Hotel check-in and check-out is smooth and easy, and it can be carried around without stress even when traveling in a city with lots of stairs and trains.

■ メリット（その上での強み）

Minimize time loss by packing your laptop, documents, and change of clothes in a compact bag and bringing it on board.
It is ideal for short business trips as you can travel without checking in your luggage.

■ Sサイズのスーツケースを買うべきか？

✅ こんな人にSサイズがおすすめ ❌ Sサイズを避けるべき人
・1〜3泊の国内旅行・出張が中心 ・4泊以上の旅行が多い
・機内持ち込みで時間を節約したい ・冬の旅行がメイン（厚手の衣類が多い）
・階段や電車移動が多い ・お土産を大量に買う予定
・荷物は必要最低限に抑えられる ・家族の荷物もまとめて入れたい
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While the S size is suitable for trips of 1 to 3 nights, depending on the length of your trip and the amount of luggage, an M size might be more convenient. For overall suitcase size selection, check out the guidelines for each number of nights as well.
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三、Sサイズスーツケースで失敗しやすいポイント

Even if it is simply called an "S-size suitcase," its usability varies greatly depending on its capacity, structure, and material.
Here are some tips to help you choose the right one without making a mistake.

1. 「Sサイズ」表記を信じて買ったら機内持ち込みNGだった

The maximum size varies depending on the airline,
Choose a model with a total size of 115cm or less , based on the following dimensions: height 55cm x width 40cm x depth 25cm.
Also, since LCCs have weight limits (7kg, 10kg, etc.), a lightweight suitcase is recommended.

2. 拡張機能を使ったら機内持ち込みできなくなった

PC (polycarbonate) material is lightweight and durable, making it a popular carry-on item.
ABS material is recommended for those who want to keep costs down.
If you travel frequently, a model with a PC + ABS hybrid structure is a safe choice.

💡New Trip's advice: Many inquiries to our customer support are from customers whose bags are no longer carry-on compliant after expansion. We recommend using the expansion feature with the assumption that your bag will be checked from the start.

3. フロントオープンを選んだら「思ったより荷物が入らなかった」

For business users, the "front-opening" type
If you mainly travel, the "double-sided opening" type is convenient.
Also, be sure to check out the additional features such as laptop storage and USB ports.

💡New Trip Key Point: Recent front-opening models have undergone improvements, with an increasing number of designs integrating the front compartment with the main compartment. For example, the New Trip 0501 suitcase features this design.

4. 冬の2泊3日でパンパンになった

Silent casters and adjustable handles ensure comfortable movement.
This difference becomes more significant for people who travel long distances frequently.

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四、失敗しないSサイズスーツケースの選び方

Here we introduce three small-size suitcases that you can choose based on your travel style and purpose .
Both models combine design and functionality, and are popular for being "lightweight and durable" and "easy to store."

1. 「外寸」で判断（キャスター・ハンドル込み）

The New Trip TriPro 0501 is perfect for those who want to be able to easily take their luggage in and out and quickly access their PC.
With its front-opening design that opens to the side, it can be used smoothly in airport waiting rooms or small hotel rooms.
Although it is carry-on size, it has plenty of PC pockets and compartments.
Perfect for business trips or a one- or two-night city stay .

2. LCC利用者は本体重量3kg以下を目安に

Next up is the 0201 Plus , recommended for travelers who prioritize functionality .
Even the small size comes with an expansion zipper so you can fit a little more inside.
In addition, it is packed with convenient features such as a USB port, caster stoppers, and luggage hooks .

3. PC素材とABS素材の違い

素材 特徴 重量 価格 おすすめの人
PC（ポリカーボネート） 軽量・耐衝撃性が高い 軽い やや高い LCC利用者・頻繁に旅行する人
ABS樹脂 価格が安い・傷に強い やや重い 安い 価格重視・たまに使う人
PC+ABS混合 軽さと耐久性を両立 中間 中間 バランス重視

4. 静音キャスターの差は想像以上

The " New Trip FINO 0502 " is a model that combines elegance and robustness.
Made from 100% PC (polycarbonate) material, it is lightweight yet resistant to scratches and impacts .
Equipped with silent casters made by HINOMOTO , it can move quietly at airports and hotels.
It has expansion features , so you don't have to worry if your luggage increases while traveling.

5. 出張ならフロントオープン、旅行ならファスナー式

Front-Opening Suitcases Recommended For:

  • Those who frequently take out their PC and documents on business trips
  • Those who want to quickly retrieve their belongings in airport lounges or hotels

Zippered (Clamshell) Suitcases Recommended For:

  • Those who prioritize luggage capacity for travel
  • Those planning to buy souvenirs
  • Those who want to maximize the use of internal storage space
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五、おすすめのSサイズスーツケース3選

Even for S-sized suitcases, different models excel in different situations, such as "for business trips," "lightweight-focused," or "storage-focused."

Here, the New Trip editorial team introduces recommended models based on "who they are suitable for," derived from actual user trends and popular features.

1. 出張・ビジネス利用が多い人におすすめ｜New Trip 0501

"I want to quickly retrieve my laptop at the airport or on the Shinkansen."

For such business users, the front-opening type 0501 is popular.

You can quickly retrieve your PC and documents from the front compartment, greatly reducing stress during security checks and travel.

It's particularly convenient for people who frequently open and close their luggage.

💡 Recommended for people who:

  • Travel frequently for business, conferences, or workcations
  • Frequently use PCs and tablets
  • Prioritize travel efficiency
New Trip 0501 スーツケース

フロントオープン・多機能モデル

New Trip 0501

Sサイズ・40L｜PC

横開きフロントオープン 静音キャスター USB充電ポート ストッパー付き スマホスタンド

¥21,980

商品を見る

■ 2. 荷物が増えやすい人におすすめ｜New Trip 0201 Plus

"My luggage tends to increase due to souvenirs on the way home..."
If this sounds like your travel style, the 0201 Plus with its expansion feature is convenient.

You can expand the capacity simply by opening a zipper, allowing you to flexibly accommodate increased luggage while traveling.

Despite its S size, it offers ample storage, making it suitable for trips of "1 to 3 nights + souvenirs."

💡 Recommended for people who:

  • Shop a lot on trips to Korea or domestic trips
  • Tend to accumulate more luggage
  • Want to use one bag for both travel and business trips
New Trip 0201plus スーツケース

拡張機能搭載・超軽量モデル

New Trip 0201Plus

Sサイズ・40L(拡張後48L)｜100%PC

ストッパー付き 拡張機能 TSAロック USBポート付き ドリンクスタンド付き

¥22,580

商品を見る

3. 軽さ・取り回し重視なら｜New Trip 0502

"I often have to use stairs."
"I want something easy for a woman to carry."
For people like that, the lightweight 0502 is a popular choice.

Made with 100% PC (polycarbonate) material, it achieves both lightness and durability.

Furthermore, HINOMOTO silent casters allow for smooth and quiet movement in stations and hotels.

For the S size, because it's used frequently, the comfort of "lightness" and "quietness" makes a bigger difference than you might imagine.

💡 Recommended for:

  • Women, students, and seniors
  • Those who frequently travel by train or use stairs
  • Those who prioritize lightness
New Trip 0505 スーツケース

大容量・HIMONOTOキャスターモデル

New Trip 0502

Sサイズ・40L(拡張後48L)｜PC

拡張機能 USB充電ポート HIMONOTO製キャスター スマホスタンド

¥19,980

商品を見る

🧩 どのモデルを選ぶべき？

モデル名 主な特徴 こんな人におすすめ
New Trip 0501 フロントオープン・出張向け PCや書類を頻繁に出し入れする人
New Trip 0201 Plus 拡張機能・多機能 荷物が増えやすい旅行派
New Trip 0502 軽量・静音 持ち運びやすさ重視の人
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Sサイズスーツケースに関するよくある質問（FAQ）

Q1. Sサイズで3泊は本当に足りますか？

A1：30〜40L前後なら2〜3泊に対応可能です。ただし、冬服や厚手コート、靴が多い場合は容量不足になりやすいため、拡張機能付きモデルがおすすめです。

Q2. 冬の旅行でもSサイズで大丈夫？

A2：1〜2泊なら問題ないことが多いですが、冬服はかさばるため注意が必要です。圧縮バッグや40L前後モデルを使うと収納しやすくなります。

Q3. 20インチなら、どの航空会社でも機内持ち込みできますか？

A3：必ずしもそうではありません。一般的な20インチは多くの航空会社で対応可能ですが、一部LCCや海外航空会社では厳しい制限があります。搭乗前に公式規定を確認しましょう。

Q4. 拡張機能を使うと機内持ち込みできなくなりますか？

A4：はい。拡張後はサイズオーバーになる場合があります。行きは機内持ち込み、帰りは預け入れで使い分ける人も多いです。

Q5. フロントオープンタイプは収納量が少ないですか？

A5：従来モデルは収納量が少なめでしたが、最近は改善されています。PCや書類を頻繁に出し入れするなら便利で、荷物量重視なら通常タイプがおすすめです。

Q6. 女性の2泊3日旅行なら何Lくらい必要ですか？

A6：一般的には35〜40L前後が使いやすいサイズです。冬服やコスメが多い場合は、40L以上や拡張機能付きモデルが安心です。

Title

まとめ

For trips or business trips of 1 to 3 nights, an S-size suitcase is the best choice.
It is lightweight and easy to handle, and can even be carried on board, saving you time at the airport and the hassle of collecting your luggage.

Among them, New Trip's small size suitcase combines functionality and design.
You can choose the perfect bag to suit your travel style, with the 0501's front-opening design, the 0502's expansion capabilities, and the 0201 Plus's multifunctionality.

May your next trip be smoother and more comfortable. Enjoy your trip freely with this lightweight S-size suitcase .

執筆・監修

New Trip編集部
本記事は、スーツケースブランド「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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