Kotatsu Buying Guide: Sizes, Futon Quilts and Heaters for a Japanese Apartment
A kotatsu is a low table with a heater underneath and a quilt (こたつ布団) on top. For one or two people in a small apartment, a 75×75 cm square table is the usual size; 105×75 cm suits two to four. Buy the table, quilt and an under-rug sized for it — or a set (こたつセット) — and look for a 300–600 W heater with a thermostat. It warms only your legs, which keeps running costs low.
Table sizes
- Square 75×75 cm (正方形): one or two people — the most common for small rooms.
- Rectangle 105×75 cm (長方形): two to four people.
- Rectangle 120×80 cm: four people; check your room space first.
- Height: standard kotatsu are low (floor sitting). ハイタイプ kotatsu suit chairs.
Quilt and rug
The quilt (こたつ布団 or こたつ掛け布団) must match the table: a quilt for a 75 cm square table is often about 185×185 cm. Thin quilts (薄掛け, 省スペース) take less floor space and are easier to wash. A rug or mat underneath (こたつ敷き布団) keeps heat from escaping into the floor.
Heaters and cost
Most heaters are 300–600 W. At ¥31 per kWh, a 300 W heater costs about ¥9 an hour at full power, but the thermostat switches it on and off, so the real cost is usually lower. Quartz and halogen heaters warm up quickly; fan heaters (ファン付き) spread heat evenly.
Living with a kotatsu
- Do not sleep in the kotatsu for long periods; it dries you out and you can get dehydrated.
- Keep the quilt away from the heater element.
- In spring, many tables work as a normal low table once the quilt is removed.
Picks with checked prices
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Kotatsu set, 75 cm square (with quilt)
【Mセール終了まで2000円OFFクーポン】 高さ調節 ハイタイプこたつ 丸型 円形 円卓 4点 セット ハイタイプ こたつ 2人掛け 2way ダイニングコタ
¥36,800（グランドリビングオーダー · checked 2026-10-24）
Why this one: Table, quilt and often an under-rug in one order — the easiest way to start.
Check on the item page: 正方形 75×75 = square table. 3点セット = table + quilt + rug. 布団付き = quilt included. W数 = heater wattage.
View on RakutenOther price levels: Budget ¥27,200Premium ¥48,675
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Kotatsu table, 105×75 cm
【10%OFFクーポン対象！】こたつ テーブル 布団 セット 北欧 デザイン スクエアこたつ イーズ 105x75cm + コーデュロイ布団 2点セット 長方形
¥32,100（KURASHI NO KATACHI · checked 2026-10-24）
Why this one: For two to four people; works as a normal low table out of season.
Check on the item page: 長方形 105×75 = rectangle. 天板リバーシブル = reversible top. 継脚 = add-on legs for extra height.
View on RakutenOther price levels: Budget ¥12,980Premium ¥29,980
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![[最大60%offセール！10/27 09:59まで] こたつ布団 省スペース 長方形 正方形 抗菌防臭 フランネル 160×160 160×190 175×1](https://thumbnail.image.rakuten.co.jp/@0_mall/carpetsingu-kaiteki/cabinet/25kotatu/9808555-01-rank.jpg?_ex=400x400)
Kotatsu quilt, thin type
[最大60%offセール！10/27 09:59まで] こたつ布団 省スペース 長方形 正方形 抗菌防臭 フランネル 160×160 160×190 175×1
¥4,680（カーペット・寝具専門 快適生活館 · checked 2026-10-24）
Why this one: Takes less floor space and fits in a home washing machine.
Check on the item page: こたつ布団 = kotatsu quilt. 薄掛け / 省スペース = thin, space-saving. Size must match your table (75 cm square ≈ 185×185 cm).
View on RakutenOther price levels: Budget ¥3,690Premium ¥10,600
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![[期間限定セール！10/27まで] こたつ 敷布団 ホットカーペット カバー こたつ敷き布団 正方形 長方形 円形 キルトラグ 洗える「 フラン 敷き布団単品](https://thumbnail.image.rakuten.co.jp/@0_mall/carpetsingu-kaiteki/cabinet/25kotatu/9808487-01-gy.jpg?_ex=400x400)
Under-kotatsu rug
[期間限定セール！10/27まで] こたつ 敷布団 ホットカーペット カバー こたつ敷き布団 正方形 長方形 円形 キルトラグ 洗える「 フラン 敷き布団単品
¥3,790（カーペット・寝具専門 快適生活館 · checked 2026-10-24）
Why this one: Stops heat escaping into the floor and makes sitting more comfortable.
Check on the item page: こたつ敷き布団 = under-rug. 厚手 = thick. ホットカーペット対応 = can go on a heated carpet.
View on RakutenOther price levels: Budget ¥3,480Premium ¥11,280
FAQ
- What size kotatsu is best for one person?
- A 75×75 cm square table with a quilt of about 185×185 cm fits most one-person apartments.
- How much electricity does a kotatsu use?
- Most heaters are 300–600 W. At ¥31/kWh, 300 W costs about ¥9 an hour at full power, usually less with the thermostat.