6-mat or 8-mat? | Choosing the Right Mat Size and Dimming

When choosing a ceiling light, a common question is, "What size, in terms of tatami mats, should I choose?"

Should you go for a 6-tatami mat size or an 8-tatami mat size? The conclusion is, if it's a close call, it's safer to choose the "larger size" and then dim it down.

Relationship Between Tatami Mat Size and Brightness (Lumens)

Ceiling lights often indicate a "〜tatami mat size," which suggests the approximate brightness (lumens) needed for a room of that size. According to guidelines from the Japan Lighting Manufacturers Association, for example, a 6-tatami mat room typically requires 2,700–3,700 lm, and an 8-tatami mat room requires 3,300–4,300 lm.

Why choose a larger size if it's a close call?

If you install a 6-tatami mat light in a 6-tatami mat room, the brightness will be "just enough." However, as lights are used for a long time, their light output gradually decreases. By choosing a more powerful 8-tatami mat light from the start, you're less likely to experience dissatisfaction, such as "I wish it were a bit brighter."

If there's dimming, "too bright" isn't an issue.

You might worry, "Won't it be too bright if I choose a larger size?" But if it has a dimming function, you can simply lower the brightness. In other words, "having plenty of headroom for brightness and then fine-tuning it with dimming" is a reliable way to choose. For a comprehensive guide to choosing, please also refer to our recommended selection and deciding factors.

In the case of lipro

Our sunlight ceiling lights are available in 6-tatami mat size (¥30,000 incl. tax) and 8-tatami mat size (¥35,000 incl. tax). Both support dimming from 0-100% brightness, allowing you to adjust the brightness to suit your room size and usage.

Summary: If it's a close call, go larger, then dim down.

If the tatami mat sizes are a close call, choose the larger size and dim it down—this is the simplest and safest way to choose.

Reference Information

• Japan Lighting Manufacturers Association, "How to Choose Residential Lighting Fixtures"
  https://www.jlma.or.jp/
• lipro "Sunlight Ceiling Light"
  https://jp.lipro.com/ja-jp/products/ceiling-light-ja